21205473715 has 8 divisors (see below), whose sum is σ = 25453045728. Its totient is φ = 16960060800.

The previous prime is 21205473713. The next prime is 21205473739. The reversal of 21205473715 is 51737450212.

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

It is not a de Polignac number, because 21205473715 - 2¹ = 21205473713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21205473713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 518086 + ... + 557515.

It is an arithmetic number, because the mean of its divisors is an integer number (3181630716).

Almost surely, 2^21205473715 is an apocalyptic number.

21205473715 is a deficient number, since it is larger than the sum of its proper divisors (4247572013).

21205473715 is a wasteful number, since it uses less digits than its factorization.

21205473715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1079549.

The product of its (nonzero) digits is 58800, while the sum is 37.

The spelling of 21205473715 in words is "twenty-one billion, two hundred five million, four hundred seventy-three thousand, seven hundred fifteen".