15222251021 has 2 divisors, whose sum is σ = 15222251022. Its totient is φ = 15222251020.

The previous prime is 15222251017. The next prime is 15222251029. The reversal of 15222251021 is 12015222251.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13803900100 + 1418350921 = 117490^2 + 37661^2 .

It is a cyclic number.

It is not a de Polignac number, because 15222251021 - 2² = 15222251017 is a prime.

It is a super-2 number, since 2×15222251021² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15222251029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7611125510 + 7611125511.

It is an arithmetic number, because the mean of its divisors is an integer number (7611125511).

Almost surely, 2^15222251021 is an apocalyptic number.

It is an amenable number.

15222251021 is a deficient number, since it is larger than the sum of its proper divisors (1).

15222251021 is an equidigital number, since it uses as much as digits as its factorization.

15222251021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 800, while the sum is 23.

Adding to 15222251021 its reverse (12015222251), we get a palindrome (27237473272).

The spelling of 15222251021 in words is "fifteen billion, two hundred twenty-two million, two hundred fifty-one thousand, twenty-one".