15851551 has 2 divisors, whose sum is σ = 15851552. Its totient is φ = 15851550.

The previous prime is 15851519. The next prime is 15851557. The reversal of 15851551 is 15515851.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15851551 - 2⁵ = 15851519 is a prime.

It is a Chen prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15851557) 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, 7925775 + 7925776.

It is an arithmetic number, because the mean of its divisors is an integer number (7925776).

Almost surely, 2^15851551 is an apocalyptic number.

15851551 is a deficient number, since it is larger than the sum of its proper divisors (1).

15851551 is an equidigital number, since it uses as much as digits as its factorization.

15851551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5000, while the sum is 31.

The square root of 15851551 is about 3981.4006329431. The cubic root of 15851551 is about 251.2024789047.

It can be divided in two parts, 1585 and 1551, that added together give a square (3136 = 56²).

The spelling of 15851551 in words is "fifteen million, eight hundred fifty-one thousand, five hundred fifty-one".