81935400970 has 16 divisors (see below), whose sum is σ = 147556878408. Its totient is φ = 32757903360.

The previous prime is 81935400889. The next prime is 81935400971. The reversal of 81935400970 is 7900453918.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 81921315961 + 14085009 = 286219^2 + 3753^2 .

It is a super-2 number, since 2×81935400970² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81935400970.

It is not an unprimeable number, because it can be changed into a prime (81935400971) 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, 2010951 + ... + 2051290.

Almost surely, 2^81935400970 is an apocalyptic number.

81935400970 is a deficient number, since it is larger than the sum of its proper divisors (65621477438).

81935400970 is a wasteful number, since it uses less digits than its factorization.

81935400970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4064265.

The product of its (nonzero) digits is 272160, while the sum is 46.

The spelling of 81935400970 in words is "eighty-one billion, nine hundred thirty-five million, four hundred thousand, nine hundred seventy".