1551656251 has 2 divisors, whose sum is σ = 1551656252. Its totient is φ = 1551656250.

The previous prime is 1551656201. The next prime is 1551656263. The reversal of 1551656251 is 1526561551.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1551656251 - 2⁷ = 1551656123 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1551656251.

It is not a weakly prime, because it can be changed into another prime (1551656201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 775828125 + 775828126.

It is an arithmetic number, because the mean of its divisors is an integer number (775828126).

Almost surely, 2^1551656251 is an apocalyptic number.

1551656251 is a deficient number, since it is larger than the sum of its proper divisors (1).

1551656251 is an equidigital number, since it uses as much as digits as its factorization.

1551656251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45000, while the sum is 37.

The square root of 1551656251 is about 39391.0681627193. The cubic root of 1551656251 is about 1157.7065891774.

The spelling of 1551656251 in words is "one billion, five hundred fifty-one million, six hundred fifty-six thousand, two hundred fifty-one".