21205473706 has 8 divisors (see below), whose sum is σ = 31809042720. Its totient is φ = 10602459468.

The previous prime is 21205473701. The next prime is 21205473713. The reversal of 21205473706 is 60737450212.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (21205473701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24246 + ... + 207361.

It is an arithmetic number, because the mean of its divisors is an integer number (3976130340).

Almost surely, 2^21205473706 is an apocalyptic number.

21205473706 is a deficient number, since it is larger than the sum of its proper divisors (10603569014).

21205473706 is a wasteful number, since it uses less digits than its factorization.

21205473706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277388.

The product of its (nonzero) digits is 70560, while the sum is 37.

The spelling of 21205473706 in words is "twenty-one billion, two hundred five million, four hundred seventy-three thousand, seven hundred six".