2156450057521 has 2 divisors, whose sum is σ = 2156450057522. Its totient is φ = 2156450057520.

The previous prime is 2156450057513. The next prime is 2156450057539. The reversal of 2156450057521 is 1257500546512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1569785973921 + 586664083600 = 1252911^2 + 765940^2 .

It is a cyclic number.

It is not a de Polignac number, because 2156450057521 - 2³ = 2156450057513 is a prime.

It is not a weakly prime, because it can be changed into another prime (2156450057591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078225028760 + 1078225028761.

It is an arithmetic number, because the mean of its divisors is an integer number (1078225028761).

Almost surely, 2^{2156450057521} is an apocalyptic number.

It is an amenable number.

2156450057521 is a deficient number, since it is larger than the sum of its proper divisors (1).

2156450057521 is an equidigital number, since it uses as much as digits as its factorization.

2156450057521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 420000, while the sum is 43.

The spelling of 2156450057521 in words is "two trillion, one hundred fifty-six billion, four hundred fifty million, fifty-seven thousand, five hundred twenty-one".