667721232 has 120 divisors (see below), whose sum is σ = 1948250304. Its totient is φ = 221387904.

The previous prime is 667721227. The next prime is 667721251. The reversal of 667721232 is 232127766.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1022218 + ... + 1022870.

Almost surely, 2^667721232 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 667721232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (974125152).

667721232 is an abundant number, since it is smaller than the sum of its proper divisors (1280529072).

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

667721232 is a wasteful number, since it uses less digits than its factorization.

667721232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 939 (or 921 counting only the distinct ones).

The product of its digits is 42336, while the sum is 36.

The square root of 667721232 is about 25840.3024750098. The cubic root of 667721232 is about 874.0408459075.

Adding to 667721232 its reverse (232127766), we get a palindrome (899848998).

The spelling of 667721232 in words is "six hundred sixty-seven million, seven hundred twenty-one thousand, two hundred thirty-two".