31855377897 has 24 divisors (see below), whose sum is σ = 54898159200. Its totient is φ = 18203072328.

The previous prime is 31855377889. The next prime is 31855377901. The reversal of 31855377897 is 79877355813.

31855377897 is a `hidden beast` number, since 3 + 1 + 8 + 5 + 537 + 7 + 8 + 97 = 666.

It is not a de Polignac number, because 31855377897 - 2³ = 31855377889 is a prime.

It is a super-2 number, since 2×31855377897² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (31855372897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12037747 + ... + 12040392.

It is an arithmetic number, because the mean of its divisors is an integer number (2287423300).

Almost surely, 2^31855377897 is an apocalyptic number.

It is an amenable number.

31855377897 is a deficient number, since it is larger than the sum of its proper divisors (23042781303).

31855377897 is a wasteful number, since it uses less digits than its factorization.

31855377897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24078162 (or 24078149 counting only the distinct ones).

The product of its digits is 44452800, while the sum is 63.

The spelling of 31855377897 in words is "thirty-one billion, eight hundred fifty-five million, three hundred seventy-seven thousand, eight hundred ninety-seven".