221660040 has 64 divisors (see below), whose sum is σ = 759980160. Its totient is φ = 50664960.

The previous prime is 221660029. The next prime is 221660041. The reversal of 221660040 is 40066122.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 221659989 and 221660016.

It is not an unprimeable number, because it can be changed into a prime (221660041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 131101 + ... + 132780.

It is an arithmetic number, because the mean of its divisors is an integer number (11874690).

Almost surely, 2^221660040 is an apocalyptic number.

221660040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221660040 is an abundant number, since it is smaller than the sum of its proper divisors (538320120).

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

221660040 is a wasteful number, since it uses less digits than its factorization.

221660040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263902 (or 263898 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 221660040 is about 14888.2517442445. The cubic root of 221660040 is about 605.1956565004.

The spelling of 221660040 in words is "two hundred twenty-one million, six hundred sixty thousand, forty".