639973451 has 8 divisors (see below), whose sum is σ = 690303264. Its totient is φ = 589800960.

The previous prime is 639973441. The next prime is 639973487. The reversal of 639973451 is 154379936.

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

It is a cyclic number.

It is not a de Polignac number, because 639973451 - 2¹⁴ = 639957067 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 639973396 and 639973405.

It is not an unprimeable number, because it can be changed into a prime (639973441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30806 + ... + 47211.

It is an arithmetic number, because the mean of its divisors is an integer number (86287908).

Almost surely, 2^639973451 is an apocalyptic number.

639973451 is a deficient number, since it is larger than the sum of its proper divisors (50329813).

639973451 is a wasteful number, since it uses less digits than its factorization.

639973451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78661.

The product of its digits is 612360, while the sum is 47.

The square root of 639973451 is about 25297.6965552202. The cubic root of 639973451 is about 861.7619595799.

The spelling of 639973451 in words is "six hundred thirty-nine million, nine hundred seventy-three thousand, four hundred fifty-one".