2504399981 has 2 divisors, whose sum is σ = 2504399982. Its totient is φ = 2504399980.

The previous prime is 2504399929. The next prime is 2504399983. The reversal of 2504399981 is 1899934052.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2489111881 + 15288100 = 49891^2 + 3910^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2504399981 is a prime.

It is a super-2 number, since 2×2504399981² = 12544038529665600722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 2504399983, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2504399983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1252199990 + 1252199991.

It is an arithmetic number, because the mean of its divisors is an integer number (1252199991).

Almost surely, 2^2504399981 is an apocalyptic number.

It is an amenable number.

2504399981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2504399981 is an equidigital number, since it uses as much as digits as its factorization.

2504399981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 699840, while the sum is 50.

The square root of 2504399981 is about 50043.9804671851. The cubic root of 2504399981 is about 1358.0045673658.

The spelling of 2504399981 in words is "two billion, five hundred four million, three hundred ninety-nine thousand, nine hundred eighty-one".