647321291 has 16 divisors (see below), whose sum is σ = 694298304. Its totient is φ = 601380864.

The previous prime is 647321287. The next prime is 647321303. The reversal of 647321291 is 192123746.

It is a cyclic number.

It is not a de Polignac number, because 647321291 - 2² = 647321287 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647321201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 608426 + ... + 609488.

It is an arithmetic number, because the mean of its divisors is an integer number (43393644).

Almost surely, 2^647321291 is an apocalyptic number.

647321291 is a deficient number, since it is larger than the sum of its proper divisors (46977013).

647321291 is a wasteful number, since it uses less digits than its factorization.

647321291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1510.

The product of its digits is 18144, while the sum is 35.

The square root of 647321291 is about 25442.5095263812. The cubic root of 647321291 is about 865.0475169638.

The spelling of 647321291 in words is "six hundred forty-seven million, three hundred twenty-one thousand, two hundred ninety-one".