15231421 has 2 divisors, whose sum is σ = 15231422. Its totient is φ = 15231420.

The previous prime is 15231401. The next prime is 15231479. The reversal of 15231421 is 12413251.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7778521 + 7452900 = 2789^2 + 2730^2 .

It is a cyclic number.

It is not a de Polignac number, because 15231421 - 2¹¹ = 15229373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15231401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7615710 + 7615711.

It is an arithmetic number, because the mean of its divisors is an integer number (7615711).

Almost surely, 2^15231421 is an apocalyptic number.

It is an amenable number.

15231421 is a deficient number, since it is larger than the sum of its proper divisors (1).

15231421 is an equidigital number, since it uses as much as digits as its factorization.

15231421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 240, while the sum is 19.

The square root of 15231421 is about 3902.7453158001. The cubic root of 15231421 is about 247.8830364601.

Adding to 15231421 its reverse (12413251), we get a palindrome (27644672).

The spelling of 15231421 in words is "fifteen million, two hundred thirty-one thousand, four hundred twenty-one".