667920 has 120 divisors (see below), whose sum is σ = 2374848. Its totient is φ = 154880.

The previous prime is 667903. The next prime is 667921. The reversal of 667920 is 29766.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×667920² = 892234252800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (667921) by changing a digit.

667920 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29029 + ... + 29051.

2⁶⁶⁷⁹²⁰ is an apocalyptic number.

667920 is a gapful number since it is divisible by the number (60) 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 667920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1187424).

667920 is an abundant number, since it is smaller than the sum of its proper divisors (1706928).

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

667920 is a wasteful number, since it uses less digits than its factorization.

667920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61 (or 44 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 667920 is about 817.2637273243. The cubic root of 667920 is about 87.4127565787.

The spelling of 667920 in words is "six hundred sixty-seven thousand, nine hundred twenty".