25778421 has 24 divisors (see below), whose sum is σ = 39424320. Its totient is φ = 16186176.

The previous prime is 25778413. The next prime is 25778449. The reversal of 25778421 is 12487752.

25778421 is a `hidden beast` number, since 2 + 577 + 84 + 2 + 1 = 666.

It is not a de Polignac number, because 25778421 - 2³ = 25778413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25778461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39520 + ... + 40166.

It is an arithmetic number, because the mean of its divisors is an integer number (1642680).

Almost surely, 2^25778421 is an apocalyptic number.

It is an amenable number.

25778421 is a deficient number, since it is larger than the sum of its proper divisors (13645899).

25778421 is a wasteful number, since it uses less digits than its factorization.

25778421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 905 (or 902 counting only the distinct ones).

The product of its digits is 31360, while the sum is 36.

The square root of 25778421 is about 5077.2454145924. The cubic root of 25778421 is about 295.4056317835.

The spelling of 25778421 in words is "twenty-five million, seven hundred seventy-eight thousand, four hundred twenty-one".