21130240542 has 64 divisors (see below), whose sum is σ = 45759458304. Its totient is φ = 6479390720.

The previous prime is 21130240529. The next prime is 21130240567. The reversal of 21130240542 is 24504203112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4221013 + ... + 4226015.

It is an arithmetic number, because the mean of its divisors is an integer number (714991536).

Almost surely, 2^21130240542 is an apocalyptic number.

21130240542 is an abundant number, since it is smaller than the sum of its proper divisors (24629217762).

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

21130240542 is a wasteful number, since it uses less digits than its factorization.

21130240542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5953.

The product of its (nonzero) digits is 1920, while the sum is 24.

Adding to 21130240542 its reverse (24504203112), we get a palindrome (45634443654).

The spelling of 21130240542 in words is "twenty-one billion, one hundred thirty million, two hundred forty thousand, five hundred forty-two".