81155384037 has 36 divisors (see below), whose sum is σ = 145068983904. Its totient is φ = 42807229920.

The previous prime is 81155383951. The next prime is 81155384099. The reversal of 81155384037 is 73048355118.

It is a happy number.

81155384037 is a `hidden beast` number, since 8 + 11 + 553 + 84 + 0 + 3 + 7 = 666.

It is not a de Polignac number, because 81155384037 - 2¹⁰ = 81155383013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81155383983 and 81155384001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81155384137) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3800539 + ... + 3821832.

Almost surely, 2^81155384037 is an apocalyptic number.

It is an amenable number.

81155384037 is a deficient number, since it is larger than the sum of its proper divisors (63913599867).

81155384037 is a wasteful number, since it uses less digits than its factorization.

81155384037 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7622410 (or 7622394 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The spelling of 81155384037 in words is "eighty-one billion, one hundred fifty-five million, three hundred eighty-four thousand, thirty-seven".