21798400213 has 16 divisors (see below), whose sum is σ = 22885099776. Its totient is φ = 20723655040.

The previous prime is 21798400193. The next prime is 21798400223. The reversal of 21798400213 is 31200489712.

It is not a de Polignac number, because 21798400213 - 2²⁹ = 21261529301 is a prime.

It is a super-2 number, since 2×21798400213² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21798400223) 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, 2784681 + ... + 2792497.

It is an arithmetic number, because the mean of its divisors is an integer number (1430318736).

Almost surely, 2^21798400213 is an apocalyptic number.

21798400213 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21798400213 is a deficient number, since it is larger than the sum of its proper divisors (1086699563).

21798400213 is a wasteful number, since it uses less digits than its factorization.

21798400213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8564.

The product of its (nonzero) digits is 24192, while the sum is 37.

Adding to 21798400213 its reverse (31200489712), we get a palindrome (52998889925).

The spelling of 21798400213 in words is "twenty-one billion, seven hundred ninety-eight million, four hundred thousand, two hundred thirteen".