15451661 has 2 divisors, whose sum is σ = 15451662. Its totient is φ = 15451660.

The previous prime is 15451651. The next prime is 15451669. The reversal of 15451661 is 16615451.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7806436 + 7645225 = 2794^2 + 2765^2 .

It is an emirp because it is prime and its reverse (16615451) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15451661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15451669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7725830 + 7725831.

It is an arithmetic number, because the mean of its divisors is an integer number (7725831).

Almost surely, 2^15451661 is an apocalyptic number.

It is an amenable number.

15451661 is a deficient number, since it is larger than the sum of its proper divisors (1).

15451661 is an equidigital number, since it uses as much as digits as its factorization.

15451661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3600, while the sum is 29.

The square root of 15451661 is about 3930.8600840020. The cubic root of 15451661 is about 249.0720854931.

It can be divided in two parts, 1545 and 1661, that multiplied together give a triangular number (2566245 = T₂₂₆₅).

The spelling of 15451661 in words is "fifteen million, four hundred fifty-one thousand, six hundred sixty-one".