6501021656 has 32 divisors (see below), whose sum is σ = 12922711680. Its totient is φ = 3060633600.

The previous prime is 6501021649. The next prime is 6501021671. The reversal of 6501021656 is 6561201056.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 345065 + ... + 363416.

It is an arithmetic number, because the mean of its divisors is an integer number (403834740).

Almost surely, 2^6501021656 is an apocalyptic number.

It is an amenable number.

6501021656 is a deficient number, since it is larger than the sum of its proper divisors (6421690024).

6501021656 is a wasteful number, since it uses less digits than its factorization.

6501021656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 708555 (or 708551 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 6501021656 is about 80628.9132755738. The cubic root of 6501021656 is about 1866.3533512970.

The spelling of 6501021656 in words is "six billion, five hundred one million, twenty-one thousand, six hundred fifty-six".