647631551 has 8 divisors (see below), whose sum is σ = 748467360. Its totient is φ = 548875008.

The previous prime is 647631527. The next prime is 647631563. The reversal of 647631551 is 155136746.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647631551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647631521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 519146 + ... + 520391.

It is an arithmetic number, because the mean of its divisors is an integer number (93558420).

Almost surely, 2^647631551 is an apocalyptic number.

647631551 is a deficient number, since it is larger than the sum of its proper divisors (100835809).

647631551 is a wasteful number, since it uses less digits than its factorization.

647631551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1039633.

The product of its digits is 75600, while the sum is 38.

The square root of 647631551 is about 25448.6060718461. The cubic root of 647631551 is about 865.1857001598.

The spelling of 647631551 in words is "six hundred forty-seven million, six hundred thirty-one thousand, five hundred fifty-one".