639473284020481 has 9 divisors (see below), whose sum is σ = 639792195776769. Its totient is φ = 639154531188036.

The previous prime is 639473284020437. The next prime is 639473284020497. The reversal of 639473284020481 is 184020482374936.

The square root of 639473284020481 is 25287809.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 639473284020481 - 2¹⁷ = 639473283889409 is a prime.

It is a super-2 number, since 2×639473284020481² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639473284027481) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 63295380876 + ... + 63295390978.

Almost surely, 2^{639473284020481} is an apocalyptic number.

639473284020481 is the 25287809-th square number.

639473284020481 is the 12643905-th centered octagonal number.

It is an amenable number.

639473284020481 is a deficient number, since it is larger than the sum of its proper divisors (318911756288).

639473284020481 is an frugal number, since it uses more digits than its factorization.

639473284020481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25212 (or 12606 counting only the distinct ones).

The product of its (nonzero) digits is 55738368, while the sum is 61.

The spelling of 639473284020481 in words is "six hundred thirty-nine trillion, four hundred seventy-three billion, two hundred eighty-four million, twenty thousand, four hundred eighty-one".