21955954 has 4 divisors (see below), whose sum is σ = 32933934. Its totient is φ = 10977976.

The previous prime is 21955943. The next prime is 21955957. The reversal of 21955954 is 45955912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21836929 + 119025 = 4673^2 + 345^2 .

It is not an unprimeable number, because it can be changed into a prime (21955957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5488987 + ... + 5488990.

Almost surely, 2^21955954 is an apocalyptic number.

21955954 is a deficient number, since it is larger than the sum of its proper divisors (10977980).

21955954 is a wasteful number, since it uses less digits than its factorization.

21955954 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10977979.

The product of its digits is 81000, while the sum is 40.

The square root of 21955954 is about 4685.7180879776. The cubic root of 21955954 is about 280.0168102152.

The spelling of 21955954 in words is "twenty-one million, nine hundred fifty-five thousand, nine hundred fifty-four".