2156221651584 has 512 divisors, whose sum is σ = 7748904683520. Its totient is φ = 513017856000.

The previous prime is 2156221651579. The next prime is 2156221651589. The reversal of 2156221651584 is 4851561226512.

It is an interprime number because it is at equal distance from previous prime (2156221651579) and next prime (2156221651589).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (2156221651589) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 50332894 + ... + 50375714.

It is an arithmetic number, because the mean of its divisors is an integer number (15134579460).

Almost surely, 2^{2156221651584} is an apocalyptic number.

2156221651584 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2156221651584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3874452341760).

2156221651584 is an abundant number, since it is smaller than the sum of its proper divisors (5592683031936).

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

2156221651584 is a wasteful number, since it uses less digits than its factorization.

2156221651584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43000 (or 42988 counting only the distinct ones).

The product of its digits is 1152000, while the sum is 48.

The spelling of 2156221651584 in words is "two trillion, one hundred fifty-six billion, two hundred twenty-one million, six hundred fifty-one thousand, five hundred eighty-four".