20813949247 has 48 divisors (see below), whose sum is σ = 27219624960. Its totient is φ = 15540460416.

The previous prime is 20813949217. The next prime is 20813949251. The reversal of 20813949247 is 74294931802.

It is not a de Polignac number, because 20813949247 - 2¹⁵ = 20813916479 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20813949247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20813949217) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6224458 + ... + 6227800.

It is an arithmetic number, because the mean of its divisors is an integer number (567075520).

Almost surely, 2^20813949247 is an apocalyptic number.

20813949247 is a deficient number, since it is larger than the sum of its proper divisors (6405675713).

20813949247 is a wasteful number, since it uses less digits than its factorization.

20813949247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3672 (or 3659 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 49.

The spelling of 20813949247 in words is "twenty billion, eight hundred thirteen million, nine hundred forty-nine thousand, two hundred forty-seven".