21205473719 has 8 divisors (see below), whose sum is σ = 22454155008. Its totient is φ = 19956936960.

The previous prime is 21205473713. The next prime is 21205473739. The reversal of 21205473719 is 91737450212.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21205473719 is a prime.

It is a super-2 number, since 2×21205473719² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

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

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 463274 + ... + 506984.

It is an arithmetic number, because the mean of its divisors is an integer number (2806769376).

Almost surely, 2^21205473719 is an apocalyptic number.

21205473719 is a deficient number, since it is larger than the sum of its proper divisors (1248681289).

21205473719 is a wasteful number, since it uses less digits than its factorization.

21205473719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72265.

The product of its (nonzero) digits is 105840, while the sum is 41.

The spelling of 21205473719 in words is "twenty-one billion, two hundred five million, four hundred seventy-three thousand, seven hundred nineteen".