2156349091820 has 384 divisors, whose sum is σ = 5990063063040. Its totient is φ = 632170091520.

The previous prime is 2156349091807. The next prime is 2156349091823. The reversal of 2156349091820 is 281909436512.

It is not an unprimeable number, because it can be changed into a prime (2156349091823) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 673226339 + ... + 673229541.

It is an arithmetic number, because the mean of its divisors is an integer number (15599122560).

Almost surely, 2^{2156349091820} is an apocalyptic number.

2156349091820 is a gapful number since it is divisible by the number (20) 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 2156349091820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2995031531520).

2156349091820 is an abundant number, since it is smaller than the sum of its proper divisors (3833713971220).

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

2156349091820 is a wasteful number, since it uses less digits than its factorization.

2156349091820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3565 (or 3563 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 50.

The spelling of 2156349091820 in words is "two trillion, one hundred fifty-six billion, three hundred forty-nine million, ninety-one thousand, eight hundred twenty".