81564298 has 8 divisors (see below), whose sum is σ = 126565380. Its totient is φ = 39375840.

The previous prime is 81564289. The next prime is 81564299. The reversal of 81564298 is 89246518.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 81414529 + 149769 = 9023^2 + 387^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (81564299) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 703083 + ... + 703198.

Almost surely, 2^81564298 is an apocalyptic number.

81564298 is a deficient number, since it is larger than the sum of its proper divisors (45001082).

81564298 is a wasteful number, since it uses less digits than its factorization.

81564298 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1406312.

The product of its digits is 138240, while the sum is 43.

The square root of 81564298 is about 9031.2954773941. The cubic root of 81564298 is about 433.6773104445.

The spelling of 81564298 in words is "eighty-one million, five hundred sixty-four thousand, two hundred ninety-eight".