25421405 has 8 divisors (see below), whose sum is σ = 31330392. Its totient is φ = 19787328.

The previous prime is 25421393. The next prime is 25421413. The reversal of 25421405 is 50412452.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6853924 + 18567481 = 2618^2 + 4309^2 .

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 25421405 - 2¹⁸ = 25159261 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68522 + ... + 68891.

It is an arithmetic number, because the mean of its divisors is an integer number (3916299).

Almost surely, 2^25421405 is an apocalyptic number.

It is an amenable number.

25421405 is a deficient number, since it is larger than the sum of its proper divisors (5908987).

25421405 is a wasteful number, since it uses less digits than its factorization.

25421405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137455.

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 25421405 is about 5041.9643989223. The cubic root of 25421405 is about 294.0355557288.

Adding to 25421405 its reverse (50412452), we get a palindrome (75833857).

The spelling of 25421405 in words is "twenty-five million, four hundred twenty-one thousand, four hundred five".