21075199930 has 16 divisors (see below), whose sum is σ = 38064837384. Its totient is φ = 8401307200.

The previous prime is 21075199921. The next prime is 21075199979. The reversal of 21075199930 is 3999157012.

It is a Cunningham number, because it is equal to 145173²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 21075199929 + 1 = 145173^2 + 1^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3593521 + ... + 3599380.

Almost surely, 2^21075199930 is an apocalyptic number.

21075199930 is a deficient number, since it is larger than the sum of its proper divisors (16989637454).

21075199930 is a wasteful number, since it uses less digits than its factorization.

21075199930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7193201.

The product of its (nonzero) digits is 153090, while the sum is 46.

The spelling of 21075199930 in words is "twenty-one billion, seventy-five million, one hundred ninety-nine thousand, nine hundred thirty".