81783901 has 8 divisors (see below), whose sum is σ = 84389760. Its totient is φ = 79214208.

The previous prime is 81783869. The next prime is 81783907. The reversal of 81783901 is 10938718.

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 81783901 - 2⁵ = 81783869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81783907) 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, 4411 + ... + 13528.

It is an arithmetic number, because the mean of its divisors is an integer number (10548720).

Almost surely, 2^81783901 is an apocalyptic number.

It is an amenable number.

81783901 is a deficient number, since it is larger than the sum of its proper divisors (2605859).

81783901 is a wasteful number, since it uses less digits than its factorization.

81783901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18083.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 81783901 is about 9043.4451952782. The cubic root of 81783901 is about 434.0661713258.

The spelling of 81783901 in words is "eighty-one million, seven hundred eighty-three thousand, nine hundred one".