20400220399 has 16 divisors (see below), whose sum is σ = 22145043424. Its totient is φ = 18681062400.

The previous prime is 20400220387. The next prime is 20400220427. The reversal of 20400220399 is 99302200402.

It is not a de Polignac number, because 20400220399 - 2¹⁵ = 20400187631 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20400220399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400220339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 846679 + ... + 870439.

It is an arithmetic number, because the mean of its divisors is an integer number (1384065214).

Almost surely, 2^20400220399 is an apocalyptic number.

20400220399 is a deficient number, since it is larger than the sum of its proper divisors (1744823025).

20400220399 is a wasteful number, since it uses less digits than its factorization.

20400220399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24298.

The product of its (nonzero) digits is 7776, while the sum is 31.

The spelling of 20400220399 in words is "twenty billion, four hundred million, two hundred twenty thousand, three hundred ninety-nine".