25501921993 has 2 divisors, whose sum is σ = 25501921994. Its totient is φ = 25501921992.

The previous prime is 25501921937. The next prime is 25501922021. The reversal of 25501921993 is 39912910552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24632674704 + 869247289 = 156948^2 + 29483^2 .

It is a cyclic number.

It is not a de Polignac number, because 25501921993 - 2¹⁷ = 25501790921 is a prime.

It is not a weakly prime, because it can be changed into another prime (25501921693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12750960996 + 12750960997.

It is an arithmetic number, because the mean of its divisors is an integer number (12750960997).

Almost surely, 2^25501921993 is an apocalyptic number.

It is an amenable number.

25501921993 is a deficient number, since it is larger than the sum of its proper divisors (1).

25501921993 is an equidigital number, since it uses as much as digits as its factorization.

25501921993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 218700, while the sum is 46.

The spelling of 25501921993 in words is "twenty-five billion, five hundred one million, nine hundred twenty-one thousand, nine hundred ninety-three".