15554681 has 2 divisors, whose sum is σ = 15554682. Its totient is φ = 15554680.

The previous prime is 15554657. The next prime is 15554713. The reversal of 15554681 is 18645551.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15085456 + 469225 = 3884^2 + 685^2 .

It is an emirp because it is prime and its reverse (18645551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15554681 - 2¹⁴ = 15538297 is a prime.

It is a super-2 number, since 2×15554681² = 483896202023522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (15554641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7777340 + 7777341.

It is an arithmetic number, because the mean of its divisors is an integer number (7777341).

Almost surely, 2^15554681 is an apocalyptic number.

It is an amenable number.

15554681 is a deficient number, since it is larger than the sum of its proper divisors (1).

15554681 is an equidigital number, since it uses as much as digits as its factorization.

15554681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24000, while the sum is 35.

The square root of 15554681 is about 3943.9423170224. The cubic root of 15554681 is about 249.6244013185.

The spelling of 15554681 in words is "fifteen million, five hundred fifty-four thousand, six hundred eighty-one".