15945551 has 2 divisors, whose sum is σ = 15945552. Its totient is φ = 15945550.

The previous prime is 15945511. The next prime is 15945571. The reversal of 15945551 is 15554951.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15945551 - 2¹⁰ = 15944527 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15945511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7972775 + 7972776.

It is an arithmetic number, because the mean of its divisors is an integer number (7972776).

Almost surely, 2^15945551 is an apocalyptic number.

15945551 is a deficient number, since it is larger than the sum of its proper divisors (1).

15945551 is an equidigital number, since it uses as much as digits as its factorization.

15945551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22500, while the sum is 35.

The square root of 15945551 is about 3993.1880747092. The cubic root of 15945551 is about 251.6980457830.

The spelling of 15945551 in words is "fifteen million, nine hundred forty-five thousand, five hundred fifty-one".