639450019457 has 16 divisors (see below), whose sum is σ = 678679879680. Its totient is φ = 601176084432.

The previous prime is 639450019441. The next prime is 639450019489. The reversal of 639450019457 is 754910054936.

It is a cyclic number.

It is not a de Polignac number, because 639450019457 - 2⁴ = 639450019441 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 639450019399 and 639450019408.

It is not an unprimeable number, because it can be changed into a prime (639450039457) 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, 8379488 + ... + 8455454.

It is an arithmetic number, because the mean of its divisors is an integer number (42417492480).

Almost surely, 2^639450019457 is an apocalyptic number.

It is an amenable number.

639450019457 is a deficient number, since it is larger than the sum of its proper divisors (39229860223).

639450019457 is a wasteful number, since it uses less digits than its factorization.

639450019457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82252.

The product of its (nonzero) digits is 4082400, while the sum is 53.

The spelling of 639450019457 in words is "six hundred thirty-nine billion, four hundred fifty million, nineteen thousand, four hundred fifty-seven".