638972435 has 8 divisors (see below), whose sum is σ = 773933616. Its totient is φ = 506400160.

The previous prime is 638972309. The next prime is 638972441. The reversal of 638972435 is 534279836.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-638972435 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 638972435.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 596636 + ... + 597705.

It is an arithmetic number, because the mean of its divisors is an integer number (96741702).

Almost surely, 2^638972435 is an apocalyptic number.

638972435 is a deficient number, since it is larger than the sum of its proper divisors (134961181).

638972435 is a wasteful number, since it uses less digits than its factorization.

638972435 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1194453.

The product of its digits is 1088640, while the sum is 47.

The square root of 638972435 is about 25277.9040863755. The cubic root of 638972435 is about 861.3124161053.

The spelling of 638972435 in words is "six hundred thirty-eight million, nine hundred seventy-two thousand, four hundred thirty-five".