21040134402 has 96 divisors (see below), whose sum is σ = 49391640000. Its totient is φ = 5957546112.

The previous prime is 21040134389. The next prime is 21040134449. The reversal of 21040134402 is 20443104012.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 25379724 + ... + 25380552.

It is an arithmetic number, because the mean of its divisors is an integer number (514496250).

Almost surely, 2^21040134402 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21040134402, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24695820000).

21040134402 is an abundant number, since it is smaller than the sum of its proper divisors (28351505598).

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

21040134402 is a wasteful number, since it uses less digits than its factorization.

21040134402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1520 (or 1513 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21040134402 its reverse (20443104012), we get a palindrome (41483238414).

The spelling of 21040134402 in words is "twenty-one billion, forty million, one hundred thirty-four thousand, four hundred two".