21374949799 has 16 divisors (see below), whose sum is σ = 25030345536. Its totient is φ = 17870227200.

The previous prime is 21374949709. The next prime is 21374949823. The reversal of 21374949799 is 99794947312.

It is not a de Polignac number, because 21374949799 - 2²¹ = 21372852647 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21374949799.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21374949709) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1883089 + ... + 1894405.

It is an arithmetic number, because the mean of its divisors is an integer number (1564396596).

Almost surely, 2^21374949799 is an apocalyptic number.

21374949799 is a deficient number, since it is larger than the sum of its proper divisors (3655395737).

21374949799 is a wasteful number, since it uses less digits than its factorization.

21374949799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17946.

The product of its digits is 30862944, while the sum is 64.

The spelling of 21374949799 in words is "twenty-one billion, three hundred seventy-four million, nine hundred forty-nine thousand, seven hundred ninety-nine".