21423014420 has 24 divisors (see below), whose sum is σ = 45095208648. Its totient is φ = 8548848000.

The previous prime is 21423014413. The next prime is 21423014429. The reversal of 21423014420 is 2441032412.

It can be written as a sum of positive squares in 4 ways, for example, as 103510276 + 21319504144 = 10174^2 + 146012^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21423014429) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1263731 + ... + 1280570.

It is an arithmetic number, because the mean of its divisors is an integer number (1878967027).

Almost surely, 2^21423014420 is an apocalyptic number.

21423014420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21423014420 is an abundant number, since it is smaller than the sum of its proper divisors (23672194228).

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

21423014420 is a wasteful number, since it uses less digits than its factorization.

21423014420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2544731 (or 2544729 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21423014420 its reverse (2441032412), we get a palindrome (23864046832).

The spelling of 21423014420 in words is "twenty-one billion, four hundred twenty-three million, fourteen thousand, four hundred twenty".