21556762878346 has 8 divisors (see below), whose sum is σ = 32345632534464. Its totient is φ = 10774885366860.

The previous prime is 21556762878341. The next prime is 21556762878481. The reversal of 21556762878346 is 64387826765512.

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

It is a super-2 number, since 2×21556762878346² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21556762878341) 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, 1748028450 + ... + 1748040781.

It is an arithmetic number, because the mean of its divisors is an integer number (4043204066808).

Almost surely, 2^{21556762878346} is an apocalyptic number.

21556762878346 is a deficient number, since it is larger than the sum of its proper divisors (10788869656118).

21556762878346 is a wasteful number, since it uses less digits than its factorization.

21556762878346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3496072316.

The product of its digits is 812851200, while the sum is 70.

The spelling of 21556762878346 in words is "twenty-one trillion, five hundred fifty-six billion, seven hundred sixty-two million, eight hundred seventy-eight thousand, three hundred forty-six".