21151215542 has 8 divisors (see below), whose sum is σ = 31731664032. Its totient is φ = 10573994200.

The previous prime is 21151215529. The next prime is 21151215577. The reversal of 21151215542 is 24551215112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 790334 + ... + 816657.

It is an arithmetic number, because the mean of its divisors is an integer number (3966458004).

Almost surely, 2^21151215542 is an apocalyptic number.

21151215542 is a deficient number, since it is larger than the sum of its proper divisors (10580448490).

21151215542 is a wasteful number, since it uses less digits than its factorization.

21151215542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1613574.

The product of its digits is 4000, while the sum is 29.

The spelling of 21151215542 in words is "twenty-one billion, one hundred fifty-one million, two hundred fifteen thousand, five hundred forty-two".