25191993 has 4 divisors (see below), whose sum is σ = 33589328. Its totient is φ = 16794660.

The previous prime is 25191989. The next prime is 25192001. The reversal of 25191993 is 39919152.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 25191993 - 2² = 25191989 is a prime.

It is a super-2 number, since 2×25191993² = 1269273022624098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25181993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4198663 + ... + 4198668.

It is an arithmetic number, because the mean of its divisors is an integer number (8397332).

Almost surely, 2^25191993 is an apocalyptic number.

It is an amenable number.

25191993 is a deficient number, since it is larger than the sum of its proper divisors (8397335).

25191993 is an equidigital number, since it uses as much as digits as its factorization.

25191993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8397334.

The product of its digits is 21870, while the sum is 39.

The square root of 25191993 is about 5019.1625795545. The cubic root of 25191993 is about 293.1483870605.

The spelling of 25191993 in words is "twenty-five million, one hundred ninety-one thousand, nine hundred ninety-three".