21342725 has 12 divisors (see below), whose sum is σ = 27319680. Its totient is φ = 16522800.

The previous prime is 21342721. The next prime is 21342773. The reversal of 21342725 is 52724312.

It is not a de Polignac number, because 21342725 - 2² = 21342721 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21342694 and 21342703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21342721) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12995 + ... + 14544.

It is an arithmetic number, because the mean of its divisors is an integer number (2276640).

Almost surely, 2^21342725 is an apocalyptic number.

21342725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21342725 is a deficient number, since it is larger than the sum of its proper divisors (5976955).

21342725 is a wasteful number, since it uses less digits than its factorization.

21342725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27580 (or 27575 counting only the distinct ones).

The product of its digits is 3360, while the sum is 26.

The square root of 21342725 is about 4619.8187193872. The cubic root of 21342725 is about 277.3852026317.

The spelling of 21342725 in words is "twenty-one million, three hundred forty-two thousand, seven hundred twenty-five".