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9997981 = 74730389
BaseRepresentation
bin100110001000…
…111010011101
3200210221122121
4212020322131
510024413411
6554142541
7150660430
oct46107235
920727577
109997981
1157096a4
123421a51
1320c0986
141483817
15d27571
hex988e9d

9997981 has 8 divisors (see below), whose sum is σ = 11669760. Its totient is φ = 8387088.

The previous prime is 9997969. The next prime is 9997987. The reversal of 9997981 is 1897999.

9997981 is digitally balanced in base 2 and base 8, because in such bases it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9997981 - 221 = 7900829 is a prime.

It is a super-2 number, since 2×99979812 = 199919248152722, which contains 22 as substring.

It is a Duffinian number.

9997981 is strictly pandigital in base 8.

9997981 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9997987) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14866 + ... + 15523.

It is an arithmetic number, because the mean of its divisors is an integer number (1458720).

Almost surely, 29997981 is an apocalyptic number.

It is an amenable number.

9997981 is a deficient number, since it is larger than the sum of its proper divisors (1671779).

9997981 is a wasteful number, since it uses less digits than its factorization.

9997981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30443.

The product of its digits is 367416, while the sum is 52.

The square root of 9997981 is about 3161.9584121237. The cubic root of 9997981 is about 215.4289686818.

The spelling of 9997981 in words is "nine million, nine hundred ninety-seven thousand, nine hundred eighty-one".

Divisors: 1 7 47 329 30389 212723 1428283 9997981