21320425 has 24 divisors (see below), whose sum is σ = 31533696. Its totient is φ = 13981440.

The previous prime is 21320407. The next prime is 21320447. The reversal of 21320425 is 52402312.

It is not a de Polignac number, because 21320425 - 2⁷ = 21320297 is a prime.

It is a super-3 number, since 3×21320425³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

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, 1377 + ... + 6673.

It is an arithmetic number, because the mean of its divisors is an integer number (1313904).

Almost surely, 2^21320425 is an apocalyptic number.

21320425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21320425 is a deficient number, since it is larger than the sum of its proper divisors (10213271).

21320425 is a wasteful number, since it uses less digits than its factorization.

21320425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5337 (or 5332 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 21320425 is about 4617.4045740004. The cubic root of 21320425 is about 277.2885600888.

Adding to 21320425 its reverse (52402312), we get a palindrome (73722737).

The spelling of 21320425 in words is "twenty-one million, three hundred twenty thousand, four hundred twenty-five".