25121663543 has 6 divisors (see below), whose sum is σ = 26261399304. Its totient is φ = 24029416796.

The previous prime is 25121663509. The next prime is 25121663603. The reversal of 25121663543 is 34536612152.

It is a de Polignac number, because none of the positive numbers 2^k-25121663543 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 25121663497 and 25121663506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25121663443) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 23743955 + ... + 23745012.

It is an arithmetic number, because the mean of its divisors is an integer number (4376899884).

Almost surely, 2^25121663543 is an apocalyptic number.

25121663543 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

25121663543 is a deficient number, since it is larger than the sum of its proper divisors (1139735761).

25121663543 is an equidigital number, since it uses as much as digits as its factorization.

25121663543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47489013 (or 47488990 counting only the distinct ones).

The product of its digits is 129600, while the sum is 38.

The spelling of 25121663543 in words is "twenty-five billion, one hundred twenty-one million, six hundred sixty-three thousand, five hundred forty-three".