21543515342 has 4 divisors (see below), whose sum is σ = 32315273016. Its totient is φ = 10771757670.

The previous prime is 21543515339. The next prime is 21543515381. The reversal of 21543515342 is 24351534512.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5385878834 + ... + 5385878837.

It is an arithmetic number, because the mean of its divisors is an integer number (8078818254).

Almost surely, 2^21543515342 is an apocalyptic number.

21543515342 is a deficient number, since it is larger than the sum of its proper divisors (10771757674).

21543515342 is a wasteful number, since it uses less digits than its factorization.

21543515342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10771757673.

The product of its digits is 72000, while the sum is 35.

The spelling of 21543515342 in words is "twenty-one billion, five hundred forty-three million, five hundred fifteen thousand, three hundred forty-two".