21145115442 has 32 divisors (see below), whose sum is σ = 46206639360. Its totient is φ = 6397632720.

The previous prime is 21145115429. The next prime is 21145115483. The reversal of 21145115442 is 24451154112.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 206692 + ... + 291567.

It is an arithmetic number, because the mean of its divisors is an integer number (1443957480).

Almost surely, 2^21145115442 is an apocalyptic number.

21145115442 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21145115442 is an abundant number, since it is smaller than the sum of its proper divisors (25061523918).

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

21145115442 is a wasteful number, since it uses less digits than its factorization.

21145115442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498918.

The product of its digits is 6400, while the sum is 30.

Adding to 21145115442 its reverse (24451154112), we get a palindrome (45596269554).

The spelling of 21145115442 in words is "twenty-one billion, one hundred forty-five million, one hundred fifteen thousand, four hundred forty-two".