15120816421 has 2 divisors, whose sum is σ = 15120816422. Its totient is φ = 15120816420.

The previous prime is 15120816329. The next prime is 15120816433. The reversal of 15120816421 is 12461802151.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14258748100 + 862068321 = 119410^2 + 29361^2 .

It is a cyclic number.

It is not a de Polignac number, because 15120816421 - 2⁹ = 15120815909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15120816461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7560408210 + 7560408211.

It is an arithmetic number, because the mean of its divisors is an integer number (7560408211).

Almost surely, 2^15120816421 is an apocalyptic number.

It is an amenable number.

15120816421 is a deficient number, since it is larger than the sum of its proper divisors (1).

15120816421 is an equidigital number, since it uses as much as digits as its factorization.

15120816421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3840, while the sum is 31.

The spelling of 15120816421 in words is "fifteen billion, one hundred twenty million, eight hundred sixteen thousand, four hundred twenty-one".