1639634434 has 4 divisors (see below), whose sum is σ = 2459451654. Its totient is φ = 819817216.

The previous prime is 1639634429. The next prime is 1639634449. The reversal of 1639634434 is 4344369361.

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

It can be written as a sum of positive squares in only one way, i.e., 1168614225 + 471020209 = 34185^2 + 21703^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409908607 + ... + 409908610.

Almost surely, 2^1639634434 is an apocalyptic number.

1639634434 is a deficient number, since it is larger than the sum of its proper divisors (819817220).

1639634434 is an equidigital number, since it uses as much as digits as its factorization.

1639634434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 819817219.

The product of its digits is 559872, while the sum is 43.

The square root of 1639634434 is about 40492.3997066116. The cubic root of 1639634434 is about 1179.1860790493.

The spelling of 1639634434 in words is "one billion, six hundred thirty-nine million, six hundred thirty-four thousand, four hundred thirty-four".