21620954 has 4 divisors (see below), whose sum is σ = 32431434. Its totient is φ = 10810476.

The previous prime is 21620953. The next prime is 21620999. The reversal of 21620954 is 45902612.

It is a happy number.

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., 20566225 + 1054729 = 4535^2 + 1027^2 .

It is not an unprimeable number, because it can be changed into a prime (21620953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5405237 + ... + 5405240.

Almost surely, 2^21620954 is an apocalyptic number.

21620954 is a deficient number, since it is larger than the sum of its proper divisors (10810480).

21620954 is a wasteful number, since it uses less digits than its factorization.

21620954 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10810479.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 21620954 is about 4649.8337604693. The cubic root of 21620954 is about 278.5853563307.

The spelling of 21620954 in words is "twenty-one million, six hundred twenty thousand, nine hundred fifty-four".