2157969408 has 176 divisors, whose sum is σ = 6710884800. Its totient is φ = 616562688.

The previous prime is 2157969391. The next prime is 2157969461. The reversal of 2157969408 is 8049697512.

It is an ABA number since it can be written as A⋅B^A, here for A=3, B=896.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (3) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 308281341 + ... + 308281347.

Almost surely, 2^2157969408 is an apocalyptic number.

2157969408 is a gapful number since it is divisible by the number (28) 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 2157969408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3355442400).

2157969408 is an abundant number, since it is smaller than the sum of its proper divisors (4552915392).

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

2157969408 is an frugal number, since it uses more digits than its factorization.

2157969408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66 (or 12 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 51.

The square root of 2157969408 is about 46453.9493261875. The cubic root of 2157969408 is about 1292.2556149954.

The spelling of 2157969408 in words is "two billion, one hundred fifty-seven million, nine hundred sixty-nine thousand, four hundred eight".