21187046 has 8 divisors (see below), whose sum is σ = 32519784. Its totient is φ = 10347120.

The previous prime is 21187027. The next prime is 21187063. The reversal of 21187046 is 64078112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21187046² = 897781836412232, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123095 + ... + 123266.

It is an arithmetic number, because the mean of its divisors is an integer number (4064973).

Almost surely, 2^21187046 is an apocalyptic number.

21187046 is a deficient number, since it is larger than the sum of its proper divisors (11332738).

21187046 is a wasteful number, since it uses less digits than its factorization.

21187046 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246406.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 21187046 is about 4602.9388438258. The cubic root of 21187046 is about 276.7091178550.

The spelling of 21187046 in words is "twenty-one million, one hundred eighty-seven thousand, forty-six".