25138121761 has 8 divisors (see below), whose sum is σ = 25783033248. Its totient is φ = 24494724000.

The previous prime is 25138121753. The next prime is 25138121803. The reversal of 25138121761 is 16712183152.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 25138121761 - 2³ = 25138121753 is a prime.

It is a super-2 number, since 2×25138121761² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25138121761.

It is not an unprimeable number, because it can be changed into a prime (25138121161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 344755 + ... + 411256.

It is an arithmetic number, because the mean of its divisors is an integer number (3222879156).

Almost surely, 2^25138121761 is an apocalyptic number.

It is an amenable number.

25138121761 is a deficient number, since it is larger than the sum of its proper divisors (644911487).

25138121761 is an equidigital number, since it uses as much as digits as its factorization.

25138121761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 756863.

The product of its digits is 20160, while the sum is 37.

The spelling of 25138121761 in words is "twenty-five billion, one hundred thirty-eight million, one hundred twenty-one thousand, seven hundred sixty-one".