25419971993 has 4 divisors (see below), whose sum is σ = 27375354468. Its totient is φ = 23464589520.

The previous prime is 25419971987. The next prime is 25419972107. The reversal of 25419971993 is 39917991452.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17465472649 + 7954499344 = 132157^2 + 89188^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25419971993 is a prime.

It is a super-2 number, since 2×25419971993² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25419971903) 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, 977691218 + ... + 977691243.

It is an arithmetic number, because the mean of its divisors is an integer number (6843838617).

Almost surely, 2^25419971993 is an apocalyptic number.

It is an amenable number.

25419971993 is a deficient number, since it is larger than the sum of its proper divisors (1955382475).

25419971993 is a wasteful number, since it uses less digits than its factorization.

25419971993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1955382474.

The product of its digits is 5511240, while the sum is 59.

The spelling of 25419971993 in words is "twenty-five billion, four hundred nineteen million, nine hundred seventy-one thousand, nine hundred ninety-three".