21740925 has 24 divisors (see below), whose sum is σ = 36131616. Its totient is φ = 11535040.

The previous prime is 21740903. The next prime is 21740963. The reversal of 21740925 is 52904712.

It is not a de Polignac number, because 21740925 - 2⁸ = 21740669 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21740892 and 21740901.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 16387 + ... + 17663.

It is an arithmetic number, because the mean of its divisors is an integer number (1505484).

Almost surely, 2^21740925 is an apocalyptic number.

21740925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21740925 is a deficient number, since it is larger than the sum of its proper divisors (14390691).

21740925 is a wasteful number, since it uses less digits than its factorization.

21740925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1517 (or 1512 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 21740925 is about 4662.7164829099. The cubic root of 21740925 is about 279.0996804701.

The spelling of 21740925 in words is "twenty-one million, seven hundred forty thousand, nine hundred twenty-five".