15315445021 has 2 divisors, whose sum is σ = 15315445022. Its totient is φ = 15315445020.

The previous prime is 15315444971. The next prime is 15315445031. The reversal of 15315445021 is 12054451351.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15100968996 + 214476025 = 122886^2 + 14645^2 .

It is a cyclic number.

It is not a de Polignac number, because 15315445021 - 2⁹ = 15315444509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15315445031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7657722510 + 7657722511.

It is an arithmetic number, because the mean of its divisors is an integer number (7657722511).

Almost surely, 2^15315445021 is an apocalyptic number.

It is an amenable number.

15315445021 is a deficient number, since it is larger than the sum of its proper divisors (1).

15315445021 is an equidigital number, since it uses as much as digits as its factorization.

15315445021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12000, while the sum is 31.

Adding to 15315445021 its reverse (12054451351), we get a palindrome (27369896372).

The spelling of 15315445021 in words is "fifteen billion, three hundred fifteen million, four hundred forty-five thousand, twenty-one".