2157431449 has 2 divisors, whose sum is σ = 2157431450. Its totient is φ = 2157431448.

The previous prime is 2157431431. The next prime is 2157431503. The reversal of 2157431449 is 9441347512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2091415824 + 66015625 = 45732^2 + 8125^2 .

It is a cyclic number.

It is not a de Polignac number, because 2157431449 - 2⁹ = 2157430937 is a prime.

It is not a weakly prime, because it can be changed into another prime (2157431429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078715724 + 1078715725.

It is an arithmetic number, because the mean of its divisors is an integer number (1078715725).

Almost surely, 2^2157431449 is an apocalyptic number.

It is an amenable number.

2157431449 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157431449 is an equidigital number, since it uses as much as digits as its factorization.

2157431449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 40.

The square root of 2157431449 is about 46448.1587256158. The cubic root of 2157431449 is about 1292.1482241753.

The spelling of 2157431449 in words is "two billion, one hundred fifty-seven million, four hundred thirty-one thousand, four hundred forty-nine".