21954025 has 12 divisors (see below), whose sum is σ = 28656400. Its totient is φ = 16638480.

The previous prime is 21954019. The next prime is 21954047. The reversal of 21954025 is 52045912.

It is not a de Polignac number, because 21954025 - 2⁹ = 21953513 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21953984 and 21954002.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22635 + ... + 23584.

Almost surely, 2^21954025 is an apocalyptic number.

21954025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21954025 is a deficient number, since it is larger than the sum of its proper divisors (6702375).

21954025 is a wasteful number, since it uses less digits than its factorization.

21954025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46248 (or 46243 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 21954025 is about 4685.5122452086. The cubic root of 21954025 is about 280.0086094292.

Adding to 21954025 its reverse (52045912), we get a palindrome (73999937).

The spelling of 21954025 in words is "twenty-one million, nine hundred fifty-four thousand, twenty-five".