21249306742 has 8 divisors (see below), whose sum is σ = 31884590232. Its totient is φ = 10621110000.

The previous prime is 21249306739. The next prime is 21249306803. The reversal of 21249306742 is 24760394212.

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

It is a junction number, because it is equal to n+sod(n) for n = 21249306695 and 21249306704.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1764184 + ... + 1776187.

It is an arithmetic number, because the mean of its divisors is an integer number (3985573779).

Almost surely, 2^21249306742 is an apocalyptic number.

21249306742 is a deficient number, since it is larger than the sum of its proper divisors (10635283490).

21249306742 is a wasteful number, since it uses less digits than its factorization.

21249306742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3543374.

The product of its (nonzero) digits is 145152, while the sum is 40.

The spelling of 21249306742 in words is "twenty-one billion, two hundred forty-nine million, three hundred six thousand, seven hundred forty-two".