15055221997 has 2 divisors, whose sum is σ = 15055221998. Its totient is φ = 15055221996.

The previous prime is 15055221991. The next prime is 15055222019. The reversal of 15055221997 is 79912255051.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10989119241 + 4066102756 = 104829^2 + 63766^2 .

It is a cyclic number.

It is not a de Polignac number, because 15055221997 - 2¹⁵ = 15055189229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15055221991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7527610998 + 7527610999.

It is an arithmetic number, because the mean of its divisors is an integer number (7527610999).

Almost surely, 2^15055221997 is an apocalyptic number.

It is an amenable number.

15055221997 is a deficient number, since it is larger than the sum of its proper divisors (1).

15055221997 is an equidigital number, since it uses as much as digits as its factorization.

15055221997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 283500, while the sum is 46.

The spelling of 15055221997 in words is "fifteen billion, fifty-five million, two hundred twenty-one thousand, nine hundred ninety-seven".