21249844490 has 128 divisors (see below), whose sum is σ = 46042698240. Its totient is φ = 6909235200.

The previous prime is 21249844487. The next prime is 21249844523. The reversal of 21249844490 is 9444894212.

It is a Curzon 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 in 63 ways as a sum of consecutive naturals, for example, 50474480 + ... + 50474900.

It is an arithmetic number, because the mean of its divisors is an integer number (359708580).

Almost surely, 2^21249844490 is an apocalyptic number.

21249844490 is an abundant number, since it is smaller than the sum of its proper divisors (24792853750).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21249844490 is a wasteful number, since it uses less digits than its factorization.

21249844490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 928.

The product of its (nonzero) digits is 663552, while the sum is 47.

The spelling of 21249844490 in words is "twenty-one billion, two hundred forty-nine million, eight hundred forty-four thousand, four hundred ninety".