15225430021 has 2 divisors, whose sum is σ = 15225430022. Its totient is φ = 15225430020.

The previous prime is 15225430019. The next prime is 15225430049. The reversal of 15225430021 is 12003452251.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12893602500 + 2331827521 = 113550^2 + 48289^2 .

It is a cyclic number.

It is not a de Polignac number, because 15225430021 - 2¹ = 15225430019 is a prime.

Together with 15225430019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15225430001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7612715010 + 7612715011.

It is an arithmetic number, because the mean of its divisors is an integer number (7612715011).

Almost surely, 2^15225430021 is an apocalyptic number.

It is an amenable number.

15225430021 is a deficient number, since it is larger than the sum of its proper divisors (1).

15225430021 is an equidigital number, since it uses as much as digits as its factorization.

15225430021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2400, while the sum is 25.

Adding to 15225430021 its reverse (12003452251), we get a palindrome (27228882272).

The spelling of 15225430021 in words is "fifteen billion, two hundred twenty-five million, four hundred thirty thousand, twenty-one".