64139431 has 4 divisors (see below), whose sum is σ = 65226600. Its totient is φ = 63052264.

The previous prime is 64139429. The next prime is 64139437. The reversal of 64139431 is 13493146.

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 64139431 - 2¹ = 64139429 is a prime.

It is a super-2 number, since 2×64139431² = 8227733218007522, 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 = 64139393 and 64139402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64139437) 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, 543496 + ... + 543613.

It is an arithmetic number, because the mean of its divisors is an integer number (16306650).

Almost surely, 2^64139431 is an apocalyptic number.

64139431 is a deficient number, since it is larger than the sum of its proper divisors (1087169).

64139431 is a wasteful number, since it uses less digits than its factorization.

64139431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1087168.

The product of its digits is 7776, while the sum is 31.

The square root of 64139431 is about 8008.7096963244. The cubic root of 64139431 is about 400.2902705566.

The spelling of 64139431 in words is "sixty-four million, one hundred thirty-nine thousand, four hundred thirty-one".