21917206770 has 32 divisors (see below), whose sum is σ = 54298114560. Its totient is φ = 5656053120.

The previous prime is 21917206741. The next prime is 21917206783. The reversal of 21917206770 is 7760271912.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11782515 + ... + 11784374.

It is an arithmetic number, because the mean of its divisors is an integer number (1696816080).

Almost surely, 2^21917206770 is an apocalyptic number.

21917206770 is an abundant number, since it is smaller than the sum of its proper divisors (32380907790).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21917206770 is a wasteful number, since it uses less digits than its factorization.

21917206770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23566930.

The product of its (nonzero) digits is 74088, while the sum is 42.

The spelling of 21917206770 in words is "twenty-one billion, nine hundred seventeen million, two hundred six thousand, seven hundred seventy".