64442531 has 4 divisors (see below), whose sum is σ = 64509072. Its totient is φ = 64375992.

The previous prime is 64442479. The next prime is 64442533. The reversal of 64442531 is 13524446.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64442531 is a prime.

It is a super-2 number, since 2×64442531² = 8305679603371922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 64442494 and 64442503.

It is not an unprimeable number, because it can be changed into a prime (64442533) 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, 31796 + ... + 33761.

It is an arithmetic number, because the mean of its divisors is an integer number (16127268).

Almost surely, 2^64442531 is an apocalyptic number.

64442531 is a deficient number, since it is larger than the sum of its proper divisors (66541).

64442531 is an equidigital number, since it uses as much as digits as its factorization.

64442531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66540.

The product of its digits is 11520, while the sum is 29.

The square root of 64442531 is about 8027.6105411262. The cubic root of 64442531 is about 400.9198227772.

Adding to 64442531 its reverse (13524446), we get a palindrome (77966977).

The spelling of 64442531 in words is "sixty-four million, four hundred forty-two thousand, five hundred thirty-one".