1251251501 has 2 divisors, whose sum is σ = 1251251502. Its totient is φ = 1251251500.

The previous prime is 1251251483. The next prime is 1251251503. The reversal of 1251251501 is 1051521521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1219057225 + 32194276 = 34915^2 + 5674^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1251251501 is a prime.

Together with 1251251503, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1251251503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625625750 + 625625751.

It is an arithmetic number, because the mean of its divisors is an integer number (625625751).

Almost surely, 2^1251251501 is an apocalyptic number.

It is an amenable number.

1251251501 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251251501 is an equidigital number, since it uses as much as digits as its factorization.

1251251501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 500, while the sum is 23.

The square root of 1251251501 is about 35373.0335283815. The cubic root of 1251251501 is about 1077.5767287267.

The spelling of 1251251501 in words is "one billion, two hundred fifty-one million, two hundred fifty-one thousand, five hundred one".