21513042342 has 32 divisors (see below), whose sum is σ = 52152831360. Its totient is φ = 6519103560.

The previous prime is 21513042311. The next prime is 21513042347. The reversal of 21513042342 is 24324031512.

21513042342 is a `hidden beast` number, since 2 + 15 + 1 + 304 + 2 + 342 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21513042347) 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, 18108028 + ... + 18109215.

It is an arithmetic number, because the mean of its divisors is an integer number (1629775980).

Almost surely, 2^21513042342 is an apocalyptic number.

21513042342 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21513042342 is an abundant number, since it is smaller than the sum of its proper divisors (30639789018).

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

21513042342 is a wasteful number, since it uses less digits than its factorization.

21513042342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36217265 (or 36217259 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

Adding to 21513042342 its reverse (24324031512), we get a palindrome (45837073854).

The spelling of 21513042342 in words is "twenty-one billion, five hundred thirteen million, forty-two thousand, three hundred forty-two".