221931996 has 96 divisors (see below), whose sum is σ = 611858688. Its totient is φ = 61724160.

The previous prime is 221931967. The next prime is 221932001. The reversal of 221931996 is 699139122.

221931996 = 1409² + 1410² + ... + 1512².

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

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, 485400 + ... + 485856.

It is an arithmetic number, because the mean of its divisors is an integer number (6373528).

Almost surely, 2^221931996 is an apocalyptic number.

221931996 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221931996, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (305929344).

221931996 is an abundant number, since it is smaller than the sum of its proper divisors (389926692).

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

221931996 is a wasteful number, since it uses less digits than its factorization.

221931996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 771 (or 769 counting only the distinct ones).

The product of its digits is 52488, while the sum is 42.

The square root of 221931996 is about 14897.3821861426. The cubic root of 221931996 is about 605.4430613778.

The spelling of 221931996 in words is "two hundred twenty-one million, nine hundred thirty-one thousand, nine hundred ninety-six".