21319946 has 4 divisors (see below), whose sum is σ = 31979922. Its totient is φ = 10659972.

The previous prime is 21319937. The next prime is 21319979. The reversal of 21319946 is 64991312.

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., 12880921 + 8439025 = 3589^2 + 2905^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5329985 + ... + 5329988.

Almost surely, 2^21319946 is an apocalyptic number.

21319946 is a deficient number, since it is larger than the sum of its proper divisors (10659976).

21319946 is a wasteful number, since it uses less digits than its factorization.

21319946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10659975.

The product of its digits is 11664, while the sum is 35.

The square root of 21319946 is about 4617.3527047433. The cubic root of 21319946 is about 277.2864834852.

The spelling of 21319946 in words is "twenty-one million, three hundred nineteen thousand, nine hundred forty-six".