251535461 has 2 divisors, whose sum is σ = 251535462. Its totient is φ = 251535460.

The previous prime is 251535439. The next prime is 251535469. The reversal of 251535461 is 164535152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 230098561 + 21436900 = 15169^2 + 4630^2 .

It is a cyclic number.

It is not a de Polignac number, because 251535461 - 2⁶ = 251535397 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 (251535469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125767730 + 125767731.

It is an arithmetic number, because the mean of its divisors is an integer number (125767731).

Almost surely, 2^251535461 is an apocalyptic number.

It is an amenable number.

251535461 is a deficient number, since it is larger than the sum of its proper divisors (1).

251535461 is an equidigital number, since it uses as much as digits as its factorization.

251535461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18000, while the sum is 32.

The square root of 251535461 is about 15859.8695139651. The cubic root of 251535461 is about 631.2475999517.

The spelling of 251535461 in words is "two hundred fifty-one million, five hundred thirty-five thousand, four hundred sixty-one".