15551761 has 2 divisors, whose sum is σ = 15551762. Its totient is φ = 15551760.

The previous prime is 15551759. The next prime is 15551779. The reversal of 15551761 is 16715551.

15551761 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12383361 + 3168400 = 3519^2 + 1780^2 .

It is a cyclic number.

It is not a de Polignac number, because 15551761 - 2¹ = 15551759 is a prime.

It is a super-2 number, since 2×15551761² = 483714540402242, which contains 22 as substring.

Together with 15551759, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (15551791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7775880 + 7775881.

It is an arithmetic number, because the mean of its divisors is an integer number (7775881).

Almost surely, 2^15551761 is an apocalyptic number.

It is an amenable number.

15551761 is a deficient number, since it is larger than the sum of its proper divisors (1).

15551761 is an equidigital number, since it uses as much as digits as its factorization.

15551761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5250, while the sum is 31.

The square root of 15551761 is about 3943.5721116774. The cubic root of 15551761 is about 249.6087801073.

The spelling of 15551761 in words is "fifteen million, five hundred fifty-one thousand, seven hundred sixty-one".