86821920 has 72 divisors (see below), whose sum is σ = 296284716. Its totient is φ = 23152128.

The previous prime is 86821913. The next prime is 86821921. The reversal of 86821920 is 2912868.

It can be written as a sum of positive squares in 2 ways, for example, as 84713616 + 2108304 = 9204^2 + 1452^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (86821921) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28707 + ... + 31586.

Almost surely, 2^86821920 is an apocalyptic number.

86821920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

86821920 is an abundant number, since it is smaller than the sum of its proper divisors (209462796).

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

86821920 is a wasteful number, since it uses less digits than its factorization.

86821920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60314 (or 60303 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 86821920 is about 9317.8280731080. The cubic root of 86821920 is about 442.8022257852.

The spelling of 86821920 in words is "eighty-six million, eight hundred twenty-one thousand, nine hundred twenty".