2170913721 has 16 divisors (see below), whose sum is σ = 2962370880. Its totient is φ = 1413758720.

The previous prime is 2170913677. The next prime is 2170913729. The reversal of 2170913721 is 1273190712.

It is a cyclic number.

It is not a de Polignac number, because 2170913721 - 2¹⁵ = 2170880953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2170913729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26820 + ... + 71141.

It is an arithmetic number, because the mean of its divisors is an integer number (185148180).

Almost surely, 2^2170913721 is an apocalyptic number.

It is an amenable number.

2170913721 is a deficient number, since it is larger than the sum of its proper divisors (791457159).

2170913721 is an equidigital number, since it uses as much as digits as its factorization.

2170913721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98136.

The product of its (nonzero) digits is 5292, while the sum is 33.

The square root of 2170913721 is about 46593.0651599570. The cubic root of 2170913721 is about 1294.8342778248.

The spelling of 2170913721 in words is "two billion, one hundred seventy million, nine hundred thirteen thousand, seven hundred twenty-one".