2156021433720 has 1536 divisors, whose sum is σ = 9357513984000. Its totient is φ = 417433927680.

The previous prime is 2156021433697. The next prime is 2156021433739. The reversal of 2156021433720 is 273341206512.

2156021433720 is a `hidden beast` number, since 2 + 1 + 5 + 602 + 1 + 43 + 3 + 7 + 2 + 0 = 666.

It is a super-3 number, since 3×2156021433720³ (a number of 38 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 5145635671 + ... + 5145636089.

It is an arithmetic number, because the mean of its divisors is an integer number (6092131500).

Almost surely, 2^{2156021433720} is an apocalyptic number.

2156021433720 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 2156021433720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4678756992000).

2156021433720 is an abundant number, since it is smaller than the sum of its proper divisors (7201492550280).

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

2156021433720 is a wasteful number, since it uses less digits than its factorization.

2156021433720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 693 (or 686 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The spelling of 2156021433720 in words is "two trillion, one hundred fifty-six billion, twenty-one million, four hundred thirty-three thousand, seven hundred twenty".