64806531 has 4 divisors (see below), whose sum is σ = 86408712. Its totient is φ = 43204352.

The previous prime is 64806509. The next prime is 64806541. The reversal of 64806531 is 13560846.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 64806531 - 2¹⁹ = 64282243 is a prime.

It is a super-2 number, since 2×64806531² = 8399772920507922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 64806492 and 64806501.

It is not an unprimeable number, because it can be changed into a prime (64806541) 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, 10801086 + ... + 10801091.

It is an arithmetic number, because the mean of its divisors is an integer number (21602178).

Almost surely, 2^64806531 is an apocalyptic number.

64806531 is a deficient number, since it is larger than the sum of its proper divisors (21602181).

64806531 is a wasteful number, since it uses less digits than its factorization.

64806531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21602180.

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 64806531 is about 8050.2503687774. The cubic root of 64806531 is about 401.6732636287.

The spelling of 64806531 in words is "sixty-four million, eight hundred six thousand, five hundred thirty-one".