21923425 has 24 divisors (see below), whose sum is σ = 28286136. Its totient is φ = 16842240.

The previous prime is 21923423. The next prime is 21923431. The reversal of 21923425 is 52432912.

It can be written as a sum of positive squares in 12 ways, for example, as 11664 + 21911761 = 108^2 + 4681^2 .

It is not a de Polignac number, because 21923425 - 2¹ = 21923423 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21923393 and 21923402.

It is not an unprimeable number, because it can be changed into a prime (21923423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 126639 + ... + 126811.

It is an arithmetic number, because the mean of its divisors is an integer number (1178589).

Almost surely, 2^21923425 is an apocalyptic number.

21923425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21923425 is a deficient number, since it is larger than the sum of its proper divisors (6362711).

21923425 is a wasteful number, since it uses less digits than its factorization.

21923425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357 (or 352 counting only the distinct ones).

The product of its digits is 4320, while the sum is 28.

The square root of 21923425 is about 4682.2457218732. The cubic root of 21923425 is about 279.8784548992.

It can be divided in two parts, 2192 and 3425, that multiplied together give a square (7507600 = 2740²).

The spelling of 21923425 in words is "twenty-one million, nine hundred twenty-three thousand, four hundred twenty-five".