251506001 has 2 divisors, whose sum is σ = 251506002. Its totient is φ = 251506000.

The previous prime is 251505979. The next prime is 251506027. The reversal of 251506001 is 100605152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 214915600 + 36590401 = 14660^2 + 6049^2 .

It is a cyclic number.

It is not a de Polignac number, because 251506001 - 2¹⁸ = 251243857 is a prime.

It is not a weakly prime, because it can be changed into another prime (251506061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125753000 + 125753001.

It is an arithmetic number, because the mean of its divisors is an integer number (125753001).

Almost surely, 2^251506001 is an apocalyptic number.

It is an amenable number.

251506001 is a deficient number, since it is larger than the sum of its proper divisors (1).

251506001 is an equidigital number, since it uses as much as digits as its factorization.

251506001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 251506001 is about 15858.9407275518. The cubic root of 251506001 is about 631.2229549437. Note that the first 3 decimals are identical.

The spelling of 251506001 in words is "two hundred fifty-one million, five hundred six thousand, one".