21422661 has 16 divisors (see below), whose sum is σ = 31065216. Its totient is φ = 13052736.

The previous prime is 21422641. The next prime is 21422689. The reversal of 21422661 is 16622412.

It is not a de Polignac number, because 21422661 - 2⁵ = 21422629 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21422641) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 1351 + ... + 6683.

It is an arithmetic number, because the mean of its divisors is an integer number (1941576).

Almost surely, 2^21422661 is an apocalyptic number.

It is an amenable number.

21422661 is a deficient number, since it is larger than the sum of its proper divisors (9642555).

21422661 is a wasteful number, since it uses less digits than its factorization.

21422661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5452.

The product of its digits is 1152, while the sum is 24.

The square root of 21422661 is about 4628.4620555861. The cubic root of 21422661 is about 277.7310728528.

The spelling of 21422661 in words is "twenty-one million, four hundred twenty-two thousand, six hundred sixty-one".