625153981 has 2 divisors, whose sum is σ = 625153982. Its totient is φ = 625153980.

The previous prime is 625153933. The next prime is 625153987. The reversal of 625153981 is 189351526.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 613354756 + 11799225 = 24766^2 + 3435^2 .

It is a cyclic number.

It is not a de Polignac number, because 625153981 - 2¹³ = 625145789 is a prime.

It is a super-2 number, since 2×625153981² = 781634999920296722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (625153987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 312576990 + 312576991.

It is an arithmetic number, because the mean of its divisors is an integer number (312576991).

Almost surely, 2^625153981 is an apocalyptic number.

It is an amenable number.

625153981 is a deficient number, since it is larger than the sum of its proper divisors (1).

625153981 is an equidigital number, since it uses as much as digits as its factorization.

625153981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64800, while the sum is 40.

The square root of 625153981 is about 25003.0794303422. The cubic root of 625153981 is about 855.0581819212.

The spelling of 625153981 in words is "six hundred twenty-five million, one hundred fifty-three thousand, nine hundred eighty-one".