21423630 has 32 divisors (see below), whose sum is σ = 51830784. Its totient is φ = 5666976.

The previous prime is 21423613. The next prime is 21423631. The reversal of 21423630 is 3632412.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21423597 and 21423606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21423631) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 999 + ... + 6621.

It is an arithmetic number, because the mean of its divisors is an integer number (1619712).

Almost surely, 2^21423630 is an apocalyptic number.

21423630 is an abundant number, since it is smaller than the sum of its proper divisors (30407154).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21423630 is a wasteful number, since it uses less digits than its factorization.

21423630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5760.

The product of its (nonzero) digits is 864, while the sum is 21.

The square root of 21423630 is about 4628.5667328019. The cubic root of 21423630 is about 277.7352602777.

The spelling of 21423630 in words is "twenty-one million, four hundred twenty-three thousand, six hundred thirty".