1231664 has 30 divisors (see below), whose sum is σ = 2777724. Its totient is φ = 527520.

The previous prime is 1231663. The next prime is 1231669. The reversal of 1231664 is 4661321.

1231664 = T₁₀₇ + T₁₀₈ + ... + T₂₀₄.

It is a happy number.

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1231663) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2 + ... + 1569.

2^1231664 is an apocalyptic number.

1231664 is a gapful number since it is divisible by the number (14) 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 1231664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1388862).

1231664 is an abundant number, since it is smaller than the sum of its proper divisors (1546060).

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

1231664 is a wasteful number, since it uses less digits than its factorization.

1231664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1593 (or 1580 counting only the distinct ones).

The product of its digits is 864, while the sum is 23.

The square root of 1231664 is about 1109.8035862260. The cubic root of 1231664 is about 107.1924216815.

Adding to 1231664 its reverse (4661321), we get a palindrome (5892985).

The spelling of 1231664 in words is "one million, two hundred thirty-one thousand, six hundred sixty-four".