2156993397 has 24 divisors (see below), whose sum is σ = 3363151064. Its totient is φ = 1324283904.

The previous prime is 2156993387. The next prime is 2156993431. The reversal of 2156993397 is 7933996512.

It is a happy number.

2156993397 is a `hidden beast` number, since 215 + 6 + 99 + 339 + 7 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 100280196 + 2056713201 = 10014^2 + 45351^2 .

It is not a de Polignac number, because 2156993397 - 2⁸ = 2156993141 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2156993347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29373 + ... + 71949.

Almost surely, 2^2156993397 is an apocalyptic number.

It is an amenable number.

2156993397 is a deficient number, since it is larger than the sum of its proper divisors (1206157667).

2156993397 is a wasteful number, since it uses less digits than its factorization.

2156993397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43029 (or 43026 counting only the distinct ones).

The product of its digits is 2755620, while the sum is 54.

The square root of 2156993397 is about 46443.4429925259. The cubic root of 2156993397 is about 1292.0607642427.

The spelling of 2156993397 in words is "two billion, one hundred fifty-six million, nine hundred ninety-three thousand, three hundred ninety-seven".