2156902021 has 8 divisors (see below), whose sum is σ = 2271060000. Its totient is φ = 2042807760.

The previous prime is 2156902009. The next prime is 2156902037. The reversal of 2156902021 is 1202096512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2156902021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2156902001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63855 + ... + 91603.

It is an arithmetic number, because the mean of its divisors is an integer number (283882500).

Almost surely, 2^2156902021 is an apocalyptic number.

It is an amenable number.

2156902021 is a deficient number, since it is larger than the sum of its proper divisors (114157979).

2156902021 is a wasteful number, since it uses less digits than its factorization.

2156902021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31859.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 2156902021 is about 46442.4592479770. The cubic root of 2156902021 is about 1292.0425189370.

Adding to 2156902021 its reverse (1202096512), we get a palindrome (3358998533).

The spelling of 2156902021 in words is "two billion, one hundred fifty-six million, nine hundred two thousand, twenty-one".