81207420372 has 48 divisors (see below), whose sum is σ = 226732972480. Its totient is φ = 24986898144.

The previous prime is 81207420319. The next prime is 81207420391. The reversal of 81207420372 is 27302470218.

81207420372 is a `hidden beast` number, since 81 + 207 + 4 + 2 + 0 + 372 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28918618 + ... + 28921425.

Almost surely, 2^81207420372 is an apocalyptic number.

It is an amenable number.

81207420372 is an abundant number, since it is smaller than the sum of its proper divisors (145525552108).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81207420372 is a wasteful number, since it uses less digits than its factorization.

81207420372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57840069 (or 57840061 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 36.

The spelling of 81207420372 in words is "eighty-one billion, two hundred seven million, four hundred twenty thousand, three hundred seventy-two".