73781820 has 192 divisors, whose sum is σ = 266112000. Its totient is φ = 16623360.

The previous prime is 73781803. The next prime is 73781821. The reversal of 73781820 is 2818737.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (73781821) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 495106 + ... + 495254.

It is an arithmetic number, because the mean of its divisors is an integer number (1386000).

Almost surely, 2^73781820 is an apocalyptic number.

73781820 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 73781820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133056000).

73781820 is an abundant number, since it is smaller than the sum of its proper divisors (192330180).

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

73781820 is a wasteful number, since it uses less digits than its factorization.

73781820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305 (or 297 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 73781820 is about 8589.6344508949. The cubic root of 73781820 is about 419.4206297248.

The spelling of 73781820 in words is "seventy-three million, seven hundred eighty-one thousand, eight hundred twenty".