221206621974 has 64 divisors (see below), whose sum is σ = 481347292608. Its totient is φ = 67363776000.

The previous prime is 221206621969. The next prime is 221206621981. The reversal of 221206621974 is 479126602122.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 34447284 + ... + 34453704.

It is an arithmetic number, because the mean of its divisors is an integer number (7521051447).

Almost surely, 2^221206621974 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221206621974, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (240673646304).

221206621974 is an abundant number, since it is smaller than the sum of its proper divisors (260140670634).

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

221206621974 is a wasteful number, since it uses less digits than its factorization.

221206621974 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10913.

The product of its (nonzero) digits is 145152, while the sum is 42.

The spelling of 221206621974 in words is "two hundred twenty-one billion, two hundred six million, six hundred twenty-one thousand, nine hundred seventy-four".