21945146 has 16 divisors (see below), whose sum is σ = 33854976. Its totient is φ = 10663536.

The previous prime is 21945137. The next prime is 21945149. The reversal of 21945146 is 64154912.

It is a super-2 number, since 2×21945146² = 963178865922632, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21945149) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14015 + ... + 15501.

It is an arithmetic number, because the mean of its divisors is an integer number (2115936).

Almost surely, 2^21945146 is an apocalyptic number.

21945146 is a deficient number, since it is larger than the sum of its proper divisors (11909830).

21945146 is a wasteful number, since it uses less digits than its factorization.

21945146 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1693.

The product of its digits is 8640, while the sum is 32.

The square root of 21945146 is about 4684.5646542662. The cubic root of 21945146 is about 279.9708558101.

The spelling of 21945146 in words is "twenty-one million, nine hundred forty-five thousand, one hundred forty-six".