21503630 has 16 divisors (see below), whose sum is σ = 40744080. Its totient is φ = 8148672.

The previous prime is 21503621. The next prime is 21503653. The reversal of 21503630 is 3630512.

It is a super-2 number, since 2×21503630² = 924812206353800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 56399 + ... + 56778.

It is an arithmetic number, because the mean of its divisors is an integer number (2546505).

Almost surely, 2^21503630 is an apocalyptic number.

21503630 is a deficient number, since it is larger than the sum of its proper divisors (19240450).

21503630 is a wasteful number, since it uses less digits than its factorization.

21503630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113203.

The product of its (nonzero) digits is 540, while the sum is 20.

The square root of 21503630 is about 4637.2006641939. The cubic root of 21503630 is about 278.0805366787.

The spelling of 21503630 in words is "twenty-one million, five hundred three thousand, six hundred thirty".