21185305494 has 8 divisors (see below), whose sum is σ = 42370611000. Its totient is φ = 7061768496.

The previous prime is 21185305433. The next prime is 21185305511. The reversal of 21185305494 is 49450358112.

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

21185305494 is an admirable number.

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, 1765442119 + ... + 1765442130.

It is an arithmetic number, because the mean of its divisors is an integer number (5296326375).

Almost surely, 2^21185305494 is an apocalyptic number.

21185305494 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21185305494 is a wasteful number, since it uses less digits than its factorization.

21185305494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3530884254.

The product of its (nonzero) digits is 172800, while the sum is 42.

The spelling of 21185305494 in words is "twenty-one billion, one hundred eighty-five million, three hundred five thousand, four hundred ninety-four".