624697981 has 2 divisors, whose sum is σ = 624697982. Its totient is φ = 624697980.

The previous prime is 624697939. The next prime is 624697991. The reversal of 624697981 is 189796426.

It is a happy number.

624697981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 432432025 + 192265956 = 20795^2 + 13866^2 .

It is a cyclic number.

It is not a de Polignac number, because 624697981 - 2¹¹ = 624695933 is a prime.

It is a super-2 number, since 2×624697981² = 780495134930952722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (624697901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 312348990 + 312348991.

It is an arithmetic number, because the mean of its divisors is an integer number (312348991).

Almost surely, 2^624697981 is an apocalyptic number.

It is an amenable number.

624697981 is a deficient number, since it is larger than the sum of its proper divisors (1).

624697981 is an equidigital number, since it uses as much as digits as its factorization.

624697981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1306368, while the sum is 52.

The square root of 624697981 is about 24993.9588900998. The cubic root of 624697981 is about 854.8502324223.

The spelling of 624697981 in words is "six hundred twenty-four million, six hundred ninety-seven thousand, nine hundred eighty-one".