2156471664 has 20 divisors (see below), whose sum is σ = 5570885256. Its totient is φ = 718823872.

The previous prime is 2156471657. The next prime is 2156471677. The reversal of 2156471664 is 4661746512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22463199 + ... + 22463294.

Almost surely, 2^2156471664 is an apocalyptic number.

2156471664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

2156471664 is an abundant number, since it is smaller than the sum of its proper divisors (3414413592).

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

2156471664 is a wasteful number, since it uses less digits than its factorization.

2156471664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44926504 (or 44926498 counting only the distinct ones).

The product of its digits is 241920, while the sum is 42.

The square root of 2156471664 is about 46437.8257888976. The cubic root of 2156471664 is about 1291.9565814022.

The spelling of 2156471664 in words is "two billion, one hundred fifty-six million, four hundred seventy-one thousand, six hundred sixty-four".