662991 has 16 divisors (see below), whose sum is σ = 1022208. Its totient is φ = 374400.

The previous prime is 662957. The next prime is 662999. The reversal of 662991 is 199266.

It is a happy number.

It is not a de Polignac number, because 662991 - 2¹³ = 654799 is a prime.

662991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (662999) 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, 2631 + ... + 2871.

It is an arithmetic number, because the mean of its divisors is an integer number (63888).

2⁶⁶²⁹⁹¹ is an apocalyptic number.

662991 is a deficient number, since it is larger than the sum of its proper divisors (359217).

662991 is a wasteful number, since it uses less digits than its factorization.

662991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 382.

The product of its digits is 5832, while the sum is 33.

The square root of 662991 is about 814.2425928432. The cubic root of 662991 is about 87.1972009735.

It can be divided in two parts, 662 and 991, that added together give a triangular number (1653 = T₅₇).

The spelling of 662991 in words is "six hundred sixty-two thousand, nine hundred ninety-one".