21813870947 has 8 divisors (see below), whose sum is σ = 23800143600. Its totient is φ = 19828130560.

The previous prime is 21813870937. The next prime is 21813870959. The reversal of 21813870947 is 74907831812.

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 not a de Polignac number, because 21813870947 - 2⁴ = 21813870931 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21813870895 and 21813870904.

It is not an unprimeable number, because it can be changed into a prime (21813870907) 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, 44822 + ... + 213627.

It is an arithmetic number, because the mean of its divisors is an integer number (2975017950).

Almost surely, 2^21813870947 is an apocalyptic number.

21813870947 is a deficient number, since it is larger than the sum of its proper divisors (1986272653).

21813870947 is a wasteful number, since it uses less digits than its factorization.

21813870947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266133.

The product of its (nonzero) digits is 677376, while the sum is 50.

The spelling of 21813870947 in words is "twenty-one billion, eight hundred thirteen million, eight hundred seventy thousand, nine hundred forty-seven".