21309699074 has 4 divisors (see below), whose sum is σ = 31964548614. Its totient is φ = 10654849536.

The previous prime is 21309699031. The next prime is 21309699077. The reversal of 21309699074 is 47099690312.

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., 12046599049 + 9263100025 = 109757^2 + 96245^2 .

It is not an unprimeable number, because it can be changed into a prime (21309699077) 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, 5327424767 + ... + 5327424770.

Almost surely, 2^21309699074 is an apocalyptic number.

21309699074 is a deficient number, since it is larger than the sum of its proper divisors (10654849540).

21309699074 is a wasteful number, since it uses less digits than its factorization.

21309699074 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10654849539.

The product of its (nonzero) digits is 734832, while the sum is 50.

The spelling of 21309699074 in words is "twenty-one billion, three hundred nine million, six hundred ninety-nine thousand, seventy-four".