81606364 has 18 divisors (see below), whose sum is σ = 166127640. Its totient is φ = 34974072.

The previous prime is 81606361. The next prime is 81606373. The reversal of 81606364 is 46360618.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81606361) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 207984 + ... + 208375.

Almost surely, 2^81606364 is an apocalyptic number.

It is an amenable number.

81606364 is an abundant number, since it is smaller than the sum of its proper divisors (84521276).

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

81606364 is a wasteful number, since it uses less digits than its factorization.

81606364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416377 (or 416368 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 81606364 is about 9033.6240789619. The cubic root of 81606364 is about 433.7518525945.

The spelling of 81606364 in words is "eighty-one million, six hundred six thousand, three hundred sixty-four".