71812020 has 96 divisors (see below), whose sum is σ = 241920000. Its totient is φ = 15548544.

The previous prime is 71811983. The next prime is 71812031. The reversal of 71812020 is 2021817.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3481 + ... + 12479.

It is an arithmetic number, because the mean of its divisors is an integer number (2520000).

Almost surely, 2^71812020 is an apocalyptic number.

71812020 is a gapful number since it is divisible by the number (70) 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 71812020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120960000).

71812020 is an abundant number, since it is smaller than the sum of its proper divisors (170107980).

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

71812020 is a wasteful number, since it uses less digits than its factorization.

71812020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9037 (or 9035 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 71812020 is about 8474.1973071200. The cubic root of 71812020 is about 415.6543989229.

Adding to 71812020 its reverse (2021817), we get a palindrome (73833837).

The spelling of 71812020 in words is "seventy-one million, eight hundred twelve thousand, twenty".