21493477850 has 48 divisors (see below), whose sum is σ = 43381910880. Its totient is φ = 7875441600.

The previous prime is 21493477849. The next prime is 21493477853. The reversal of 21493477850 is 5877439412.

It is a Harshad number since it is a multiple of its sum of digits (50).

It is not an unprimeable number, because it can be changed into a prime (21493477853) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41060 + ... + 211359.

It is an arithmetic number, because the mean of its divisors is an integer number (903789810).

Almost surely, 2^21493477850 is an apocalyptic number.

21493477850 is an abundant number, since it is smaller than the sum of its proper divisors (21888433030).

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

21493477850 is a wasteful number, since it uses less digits than its factorization.

21493477850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252575 (or 252570 counting only the distinct ones).

The product of its (nonzero) digits is 1693440, while the sum is 50.

The spelling of 21493477850 in words is "twenty-one billion, four hundred ninety-three million, four hundred seventy-seven thousand, eight hundred fifty".