20400321020 has 24 divisors (see below), whose sum is σ = 42992066544. Its totient is φ = 8131291776.

The previous prime is 20400320989. The next prime is 20400321041. The reversal of 20400321020 is 2012300402.

It is a junction number, because it is equal to n+sod(n) for n = 20400320986 and 20400321004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1796489 + ... + 1807808.

It is an arithmetic number, because the mean of its divisors is an integer number (1791336106).

Almost surely, 2^20400321020 is an apocalyptic number.

20400321020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20400321020 is an abundant number, since it is smaller than the sum of its proper divisors (22591745524).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20400321020 is a wasteful number, since it uses less digits than its factorization.

20400321020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3604589 (or 3604587 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

Adding to 20400321020 its reverse (2012300402), we get a palindrome (22412621422).

The spelling of 20400321020 in words is "twenty billion, four hundred million, three hundred twenty-one thousand, twenty".