64440031 has 4 divisors (see below), whose sum is σ = 64584000. Its totient is φ = 64296064.

The previous prime is 64440029. The next prime is 64440049. The reversal of 64440031 is 13004446.

It is a happy number.

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 64440031 - 2¹ = 64440029 is a prime.

It is a super-2 number, since 2×64440031² = 8305035190561922, 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 = 64439984 and 64440011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64440011) 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, 71311 + ... + 72208.

It is an arithmetic number, because the mean of its divisors is an integer number (16146000).

Almost surely, 2^64440031 is an apocalyptic number.

64440031 is a deficient number, since it is larger than the sum of its proper divisors (143969).

64440031 is a wasteful number, since it uses less digits than its factorization.

64440031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143968.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 64440031 is about 8027.4548270295. The cubic root of 64440031 is about 400.9146382481.

Adding to 64440031 its reverse (13004446), we get a palindrome (77444477).

The spelling of 64440031 in words is "sixty-four million, four hundred forty thousand, thirty-one".