2157456397 has 2 divisors, whose sum is σ = 2157456398. Its totient is φ = 2157456396.

The previous prime is 2157456359. The next prime is 2157456401. The reversal of 2157456397 is 7936547512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1857092836 + 300363561 = 43094^2 + 17331^2 .

It is a cyclic number.

It is not a de Polignac number, because 2157456397 - 2¹⁵ = 2157423629 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2157456397.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2157456307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078728198 + 1078728199.

It is an arithmetic number, because the mean of its divisors is an integer number (1078728199).

Almost surely, 2^2157456397 is an apocalyptic number.

It is an amenable number.

2157456397 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157456397 is an equidigital number, since it uses as much as digits as its factorization.

2157456397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1587600, while the sum is 49.

The square root of 2157456397 is about 46448.4272823096. The cubic root of 2157456397 is about 1292.1532048496.

The spelling of 2157456397 in words is "two billion, one hundred fifty-seven million, four hundred fifty-six thousand, three hundred ninety-seven".