1639744431 has 16 divisors (see below), whose sum is σ = 2382877056. Its totient is φ = 996914016.

The previous prime is 1639744427. The next prime is 1639744433. The reversal of 1639744431 is 1344479361.

It is not a de Polignac number, because 1639744431 - 2² = 1639744427 is a prime.

It is a super-2 number, since 2×1639744431² = 5377523597991027522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1639744433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 250045 + ... + 256518.

It is an arithmetic number, because the mean of its divisors is an integer number (148929816).

Almost surely, 2^1639744431 is an apocalyptic number.

1639744431 is a deficient number, since it is larger than the sum of its proper divisors (743132625).

1639744431 is a wasteful number, since it uses less digits than its factorization.

1639744431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 506662.

The product of its digits is 217728, while the sum is 42.

The square root of 1639744431 is about 40493.7579263768. The cubic root of 1639744431 is about 1179.2124475349.

The spelling of 1639744431 in words is "one billion, six hundred thirty-nine million, seven hundred forty-four thousand, four hundred thirty-one".