221697000 has 640 divisors, whose sum is σ = 978531840. Its totient is φ = 45619200.

The previous prime is 221696999. The next prime is 221697001. The reversal of 221697000 is 796122.

It is an interprime number because it is at equal distance from previous prime (221696999) and next prime (221697001).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221697001) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 9638989 + ... + 9639011.

It is an arithmetic number, because the mean of its divisors is an integer number (1528956).

Almost surely, 2^221697000 is an apocalyptic number.

221697000 is a gapful number since it is divisible by the number (20) 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 221697000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (489265920).

221697000 is an abundant number, since it is smaller than the sum of its proper divisors (756834840).

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

221697000 is a wasteful number, since it uses less digits than its factorization.

221697000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 221697000 is about 14889.4929396538. The cubic root of 221697000 is about 605.2292917741.

The spelling of 221697000 in words is "two hundred twenty-one million, six hundred ninety-seven thousand".