21782425 has 12 divisors (see below), whose sum is σ = 30869056. Its totient is φ = 14936400.

The previous prime is 21782419. The next prime is 21782447. The reversal of 21782425 is 52428712.

It is a happy number.

It is not a de Polignac number, because 21782425 - 2¹¹ = 21780377 is a prime.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 62061 + ... + 62410.

Almost surely, 2^21782425 is an apocalyptic number.

21782425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21782425 is a deficient number, since it is larger than the sum of its proper divisors (9086631).

21782425 is a wasteful number, since it uses less digits than its factorization.

21782425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124488 (or 124483 counting only the distinct ones).

The product of its digits is 8960, while the sum is 31.

The square root of 21782425 is about 4667.1645567732. The cubic root of 21782425 is about 279.2771533656.

The spelling of 21782425 in words is "twenty-one million, seven hundred eighty-two thousand, four hundred twenty-five".