251772649 has 2 divisors, whose sum is σ = 251772650. Its totient is φ = 251772648.

The previous prime is 251772641. The next prime is 251772659. The reversal of 251772649 is 946277152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132089049 + 119683600 = 11493^2 + 10940^2 .

It is a cyclic number.

It is not a de Polignac number, because 251772649 - 2³ = 251772641 is a prime.

It is not a weakly prime, because it can be changed into another prime (251772641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125886324 + 125886325.

It is an arithmetic number, because the mean of its divisors is an integer number (125886325).

Almost surely, 2^251772649 is an apocalyptic number.

It is an amenable number.

251772649 is a deficient number, since it is larger than the sum of its proper divisors (1).

251772649 is an equidigital number, since it uses as much as digits as its factorization.

251772649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 211680, while the sum is 43.

The square root of 251772649 is about 15867.3453671369. The cubic root of 251772649 is about 631.4459514663.

The spelling of 251772649 in words is "two hundred fifty-one million, seven hundred seventy-two thousand, six hundred forty-nine".