15553969 has 2 divisors, whose sum is σ = 15553970. Its totient is φ = 15553968.

The previous prime is 15553939. The next prime is 15553981. The reversal of 15553969 is 96935551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13593969 + 1960000 = 3687^2 + 1400^2 .

It is an emirp because it is prime and its reverse (96935551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15553969 - 2¹⁵ = 15521201 is a prime.

It is a super-2 number, since 2×15553969² = 483851903305922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (15553939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7776984 + 7776985.

It is an arithmetic number, because the mean of its divisors is an integer number (7776985).

Almost surely, 2^15553969 is an apocalyptic number.

It is an amenable number.

15553969 is a deficient number, since it is larger than the sum of its proper divisors (1).

15553969 is an equidigital number, since it uses as much as digits as its factorization.

15553969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 182250, while the sum is 43.

The square root of 15553969 is about 3943.8520509776. The cubic root of 15553969 is about 249.6205924911.

The spelling of 15553969 in words is "fifteen million, five hundred fifty-three thousand, nine hundred sixty-nine".