21319930 has 16 divisors (see below), whose sum is σ = 39699720. Its totient is φ = 8233792.

The previous prime is 21319889. The next prime is 21319937. The reversal of 21319930 is 3991312.

It can be written as a sum of positive squares in 4 ways, for example, as 20602521 + 717409 = 4539^2 + 847^2 .

It is not an unprimeable number, because it can be changed into a prime (21319937) 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, 36469 + ... + 37048.

Almost surely, 2^21319930 is an apocalyptic number.

21319930 is a deficient number, since it is larger than the sum of its proper divisors (18379790).

21319930 is a wasteful number, since it uses less digits than its factorization.

21319930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73553.

The product of its (nonzero) digits is 1458, while the sum is 28.

The square root of 21319930 is about 4617.3509721484. The cubic root of 21319930 is about 277.2864141200.

The spelling of 21319930 in words is "twenty-one million, three hundred nineteen thousand, nine hundred thirty".