2506691921 has 2 divisors, whose sum is σ = 2506691922. Its totient is φ = 2506691920.

The previous prime is 2506691917. The next prime is 2506691927. The reversal of 2506691921 is 1291966052.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1852355521 + 654336400 = 43039^2 + 25580^2 .

It is a cyclic number.

It is not a de Polignac number, because 2506691921 - 2² = 2506691917 is a prime.

It is not a weakly prime, because it can be changed into another prime (2506691927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1253345960 + 1253345961.

It is an arithmetic number, because the mean of its divisors is an integer number (1253345961).

Almost surely, 2^2506691921 is an apocalyptic number.

It is an amenable number.

2506691921 is a deficient number, since it is larger than the sum of its proper divisors (1).

2506691921 is an equidigital number, since it uses as much as digits as its factorization.

2506691921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 58320, while the sum is 41.

The square root of 2506691921 is about 50066.8744880285. The cubic root of 2506691921 is about 1358.4187072824.

The spelling of 2506691921 in words is "two billion, five hundred six million, six hundred ninety-one thousand, nine hundred twenty-one".