25991220450 has 48 divisors (see below), whose sum is σ = 69416557056. Its totient is φ = 6397838400.

The previous prime is 25991220427. The next prime is 25991220469. The reversal of 25991220450 is 5402219952.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a junction number, because it is equal to n+sod(n) for n = 25991220399 and 25991220408.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6662466 + ... + 6666365.

It is an arithmetic number, because the mean of its divisors is an integer number (1446178272).

Almost surely, 2^25991220450 is an apocalyptic number.

25991220450 is an abundant number, since it is smaller than the sum of its proper divisors (43425336606).

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

25991220450 is a wasteful number, since it uses less digits than its factorization.

25991220450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13328859 (or 13328854 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 39.

The spelling of 25991220450 in words is "twenty-five billion, nine hundred ninety-one million, two hundred twenty thousand, four hundred fifty".