81241655524 has 6 divisors (see below), whose sum is σ = 142172897174. Its totient is φ = 40620827760.

The previous prime is 81241655507. The next prime is 81241655557. The reversal of 81241655524 is 42555614218.

It can be written as a sum of positive squares in only one way, i.e., 61842737124 + 19398918400 = 248682^2 + 139280^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10155206937 + ... + 10155206944.

Almost surely, 2^81241655524 is an apocalyptic number.

It is an amenable number.

81241655524 is a deficient number, since it is larger than the sum of its proper divisors (60931241650).

81241655524 is a wasteful number, since it uses less digits than its factorization.

81241655524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20310413885 (or 20310413883 counting only the distinct ones).

The product of its digits is 384000, while the sum is 43.

The spelling of 81241655524 in words is "eighty-one billion, two hundred forty-one million, six hundred fifty-five thousand, five hundred twenty-four".