21421245794 has 16 divisors (see below), whose sum is σ = 36639054648. Its totient is φ = 9305156352.

The previous prime is 21421245787. The next prime is 21421245841. The reversal of 21421245794 is 49754212412.

It can be written as a sum of positive squares in 4 ways, for example, as 21341411569 + 79834225 = 146087^2 + 8935^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24231737 + ... + 24232620.

Almost surely, 2^21421245794 is an apocalyptic number.

21421245794 is a deficient number, since it is larger than the sum of its proper divisors (15217808854).

21421245794 is a wasteful number, since it uses less digits than its factorization.

21421245794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48464389.

The product of its digits is 161280, while the sum is 41.

The spelling of 21421245794 in words is "twenty-one billion, four hundred twenty-one million, two hundred forty-five thousand, seven hundred ninety-four".