81974770 has 16 divisors (see below), whose sum is σ = 150986880. Its totient is φ = 32027184.

The previous prime is 81974741. The next prime is 81974771. The reversal of 81974770 is 7747918.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is not an unprimeable number, because it can be changed into a prime (81974771) 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, 94890 + ... + 95749.

It is an arithmetic number, because the mean of its divisors is an integer number (9436680).

Almost surely, 2^81974770 is an apocalyptic number.

81974770 is a deficient number, since it is larger than the sum of its proper divisors (69012110).

81974770 is a wasteful number, since it uses less digits than its factorization.

81974770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190689.

The product of its (nonzero) digits is 98784, while the sum is 43.

The square root of 81974770 is about 9053.9919372617. The cubic root of 81974770 is about 434.4035865803.

The spelling of 81974770 in words is "eighty-one million, nine hundred seventy-four thousand, seven hundred seventy".