812136720 has 40 divisors (see below), whose sum is σ = 2517624576. Its totient is φ = 216569728.

The previous prime is 812136713. The next prime is 812136749. The reversal of 812136720 is 27631218.

It is a tau number, because it is divible by the number of its divisors (40).

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

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1691712 + ... + 1692191.

Almost surely, 2^812136720 is an apocalyptic number.

812136720 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

812136720 is an abundant number, since it is smaller than the sum of its proper divisors (1705487856).

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

812136720 is a wasteful number, since it uses less digits than its factorization.

812136720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3383919 (or 3383913 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 812136720 is about 28498.0125622823. The cubic root of 812136720 is about 932.9886970206.

Adding to 812136720 its reverse (27631218), we get a palindrome (839767938).

The spelling of 812136720 in words is "eight hundred twelve million, one hundred thirty-six thousand, seven hundred twenty".