21395954 has 4 divisors (see below), whose sum is σ = 32093934. Its totient is φ = 10697976.

The previous prime is 21395947. The next prime is 21395963. The reversal of 21395954 is 45959312.

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., 21390625 + 5329 = 4625^2 + 73^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5348987 + ... + 5348990.

Almost surely, 2^21395954 is an apocalyptic number.

21395954 is a deficient number, since it is larger than the sum of its proper divisors (10697980).

21395954 is a wasteful number, since it uses less digits than its factorization.

21395954 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10697979.

The product of its digits is 48600, while the sum is 38.

The square root of 21395954 is about 4625.5760722314. The cubic root of 21395954 is about 277.6156118115.

The spelling of 21395954 in words is "twenty-one million, three hundred ninety-five thousand, nine hundred fifty-four".