16221551640 has 128 divisors (see below), whose sum is σ = 58888373760. Its totient is φ = 3489675264.

The previous prime is 16221551611. The next prime is 16221551707. The reversal of 16221551640 is 4615512261.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 553702 + ... + 582261.

It is an arithmetic number, because the mean of its divisors is an integer number (460065420).

Almost surely, 2^16221551640 is an apocalyptic number.

16221551640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16221551640 is an abundant number, since it is smaller than the sum of its proper divisors (42666822120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16221551640 is a wasteful number, since it uses less digits than its factorization.

16221551640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1136001 (or 1135997 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 33.

The spelling of 16221551640 in words is "sixteen billion, two hundred twenty-one million, five hundred fifty-one thousand, six hundred forty".