21906130 has 8 divisors (see below), whose sum is σ = 39431052. Its totient is φ = 8762448.

The previous prime is 21906113. The next prime is 21906151. The reversal of 21906130 is 3160912.

It can be written as a sum of positive squares in 2 ways, for example, as 21261321 + 644809 = 4611^2 + 803^2 .

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

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 3 ways as a sum of consecutive naturals, for example, 1095297 + ... + 1095316.

Almost surely, 2^21906130 is an apocalyptic number.

21906130 is a deficient number, since it is larger than the sum of its proper divisors (17524922).

21906130 is a wasteful number, since it uses less digits than its factorization.

21906130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2190620.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 21906130 is about 4680.3984873085. The cubic root of 21906130 is about 279.8048384928.

The spelling of 21906130 in words is "twenty-one million, nine hundred six thousand, one hundred thirty".