21491723426 has 8 divisors (see below), whose sum is σ = 32417683920. Its totient is φ = 10685828788.

The previous prime is 21491723329. The next prime is 21491723551. The reversal of 21491723426 is 62432719412.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30016016 + ... + 30016731.

It is an arithmetic number, because the mean of its divisors is an integer number (4052210490).

Almost surely, 2^21491723426 is an apocalyptic number.

21491723426 is a deficient number, since it is larger than the sum of its proper divisors (10925960494).

21491723426 is a wasteful number, since it uses less digits than its factorization.

21491723426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60032928.

The product of its digits is 145152, while the sum is 41.

The spelling of 21491723426 in words is "twenty-one billion, four hundred ninety-one million, seven hundred twenty-three thousand, four hundred twenty-six".