221686740990 has 384 divisors, whose sum is σ = 727995340800. Its totient is φ = 45994936320.

The previous prime is 221686740949. The next prime is 221686741019. The reversal of 221686740990 is 99047686122.

221686740990 is a `hidden beast` number, since 221 + 6 + 8 + 6 + 7 + 409 + 9 + 0 = 666.

It is a super-2 number, since 2×221686740990² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 11483266 + ... + 11502554.

It is an arithmetic number, because the mean of its divisors is an integer number (1895821200).

Almost surely, 2^221686740990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221686740990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (363997670400).

221686740990 is an abundant number, since it is smaller than the sum of its proper divisors (506308599810).

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

221686740990 is a wasteful number, since it uses less digits than its factorization.

221686740990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19392 (or 19389 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 54.

The spelling of 221686740990 in words is "two hundred twenty-one billion, six hundred eighty-six million, seven hundred forty thousand, nine hundred ninety".