812640 has 48 divisors (see below), whose sum is σ = 2561328. Its totient is φ = 216576.

The previous prime is 812639. The next prime is 812641. The reversal of 812640 is 46218.

It is an interprime number because it is at equal distance from previous prime (812639) and next prime (812641).

It is a tau number, because it is divible by the number of its divisors (48).

It is a nialpdrome in base 16.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (812641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 367 + ... + 1326.

It is an arithmetic number, because the mean of its divisors is an integer number (53361).

2⁸¹²⁶⁴⁰ is an apocalyptic number.

812640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

812640 is an abundant number, since it is smaller than the sum of its proper divisors (1748688).

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

812640 is a wasteful number, since it uses less digits than its factorization.

812640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1711 (or 1703 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 812640 is about 901.4654735485. The cubic root of 812640 is about 93.3181381158.

Adding to 812640 its reverse (46218), we get a palindrome (858858).

The spelling of 812640 in words is "eight hundred twelve thousand, six hundred forty".