81564050 has 24 divisors (see below), whose sum is σ = 153422100. Its totient is φ = 32257280.

The previous prime is 81564023. The next prime is 81564061. The reversal of 81564050 is 5046518.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 17131321 + 64432729 = 4139^2 + 8027^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4715 + ... + 13614.

Almost surely, 2^81564050 is an apocalyptic number.

81564050 is a deficient number, since it is larger than the sum of its proper divisors (71858050).

81564050 is a wasteful number, since it uses less digits than its factorization.

81564050 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18430 (or 18425 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 81564050 is about 9031.2817473490. The cubic root of 81564050 is about 433.6768709054.

The spelling of 81564050 in words is "eighty-one million, five hundred sixty-four thousand, fifty".