87020123656 has 8 divisors (see below), whose sum is σ = 163162731870. Its totient is φ = 43510061824.

The previous prime is 87020123629. The next prime is 87020123693. The reversal of 87020123656 is 65632102078.

It can be written as a sum of positive squares in only one way, i.e., 86573646756 + 446476900 = 294234^2 + 21130^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×87020123656² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5438757721 + ... + 5438757736.

Almost surely, 2^87020123656 is an apocalyptic number.

It is an amenable number.

87020123656 is a deficient number, since it is larger than the sum of its proper divisors (76142608214).

87020123656 is a wasteful number, since it uses less digits than its factorization.

87020123656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10877515463 (or 10877515459 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 40.

The spelling of 87020123656 in words is "eighty-seven billion, twenty million, one hundred twenty-three thousand, six hundred fifty-six".