25212121454440 has 64 divisors (see below), whose sum is σ = 59738784336000. Its totient is φ = 9549928661760.

The previous prime is 25212121454413. The next prime is 25212121454473. The reversal of 25212121454440 is 4445412121252.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 25212121454440.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5428756 + ... + 8938435.

It is an arithmetic number, because the mean of its divisors is an integer number (933418505250).

Almost surely, 2^{25212121454440} is an apocalyptic number.

25212121454440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25212121454440 is an abundant number, since it is smaller than the sum of its proper divisors (34526662881560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25212121454440 is a wasteful number, since it uses less digits than its factorization.

25212121454440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14369530 (or 14369526 counting only the distinct ones).

The product of its (nonzero) digits is 102400, while the sum is 37.

Adding to 25212121454440 its reverse (4445412121252), we get a palindrome (29657533575692).

The spelling of 25212121454440 in words is "twenty-five trillion, two hundred twelve billion, one hundred twenty-one million, four hundred fifty-four thousand, four hundred forty".