21134344420 has 48 divisors (see below), whose sum is σ = 52927757568. Its totient is φ = 6931013760.

The previous prime is 21134344381. The next prime is 21134344421. The reversal of 21134344420 is 2444343112.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (21134344421) 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, 3278511 + ... + 3284950.

It is an arithmetic number, because the mean of its divisors is an integer number (1102661616).

Almost surely, 2^21134344420 is an apocalyptic number.

21134344420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21134344420 is an abundant number, since it is smaller than the sum of its proper divisors (31793413148).

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

21134344420 is a wasteful number, since it uses less digits than its factorization.

21134344420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6563500 (or 6563498 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 28.

Adding to 21134344420 its reverse (2444343112), we get a palindrome (23578687532).

The spelling of 21134344420 in words is "twenty-one billion, one hundred thirty-four million, three hundred forty-four thousand, four hundred twenty".