6351887721 has 8 divisors (see below), whose sum is σ = 8488303200. Its totient is φ = 4225032032.

The previous prime is 6351887687. The next prime is 6351887741. The reversal of 6351887721 is 1277881536.

It is a happy number.

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 6351887721 - 2⁶ = 6351887657 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6351887741) 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, 2388396 + ... + 2391053.

It is an arithmetic number, because the mean of its divisors is an integer number (1061037900).

Almost surely, 2^6351887721 is an apocalyptic number.

It is an amenable number.

6351887721 is a deficient number, since it is larger than the sum of its proper divisors (2136415479).

6351887721 is a wasteful number, since it uses less digits than its factorization.

6351887721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4779895.

The product of its digits is 564480, while the sum is 48.

The square root of 6351887721 is about 79698.7309873877. The cubic root of 6351887721 is about 1851.9713800006.

The spelling of 6351887721 in words is "six billion, three hundred fifty-one million, eight hundred eighty-seven thousand, seven hundred twenty-one".