221687064 has 64 divisors (see below), whose sum is σ = 642585600. Its totient is φ = 70681248.

The previous prime is 221687051. The next prime is 221687077. The reversal of 221687064 is 460786122.

221687064 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (221687051) and next prime (221687077).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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, 17344 + ... + 27279.

It is an arithmetic number, because the mean of its divisors is an integer number (10040400).

Almost surely, 2^221687064 is an apocalyptic number.

221687064 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

221687064 is an abundant number, since it is smaller than the sum of its proper divisors (420898536).

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

221687064 is a wasteful number, since it uses less digits than its factorization.

221687064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44661 (or 44651 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 221687064 is about 14889.1592778101. The cubic root of 221687064 is about 605.2202499316.

The spelling of 221687064 in words is "two hundred twenty-one million, six hundred eighty-seven thousand, sixty-four".