21409930779 has 32 divisors (see below), whose sum is σ = 29275271424. Its totient is φ = 13914432000.

The previous prime is 21409930769. The next prime is 21409930807. The reversal of 21409930779 is 97703990412.

It is not a de Polignac number, because 21409930779 - 2¹¹ = 21409928731 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21409930709) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7529332 + ... + 7532174.

It is an arithmetic number, because the mean of its divisors is an integer number (914852232).

Almost surely, 2^21409930779 is an apocalyptic number.

21409930779 is a deficient number, since it is larger than the sum of its proper divisors (7865340645).

21409930779 is a wasteful number, since it uses less digits than its factorization.

21409930779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3307.

The product of its (nonzero) digits is 857304, while the sum is 51.

The spelling of 21409930779 in words is "twenty-one billion, four hundred nine million, nine hundred thirty thousand, seven hundred seventy-nine".