21611954 has 16 divisors (see below), whose sum is σ = 39899328. Its totient is φ = 8549712.

The previous prime is 21611939. The next prime is 21611957. The reversal of 21611954 is 45911612.

It is not an unprimeable number, because it can be changed into a prime (21611957) 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, 59192 + ... + 59555.

It is an arithmetic number, because the mean of its divisors is an integer number (2493708).

Almost surely, 2^21611954 is an apocalyptic number.

21611954 is a deficient number, since it is larger than the sum of its proper divisors (18287374).

21611954 is a wasteful number, since it uses less digits than its factorization.

21611954 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118769.

The product of its digits is 2160, while the sum is 29.

The square root of 21611954 is about 4648.8658832021. The cubic root of 21611954 is about 278.5466960541.

The spelling of 21611954 in words is "twenty-one million, six hundred eleven thousand, nine hundred fifty-four".