81882780 has 192 divisors, whose sum is σ = 285573120. Its totient is φ = 17107200.

The previous prime is 81882763. The next prime is 81882797. The reversal of 81882780 is 8728818.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81882763) and next prime (81882797).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 247215 + ... + 247545.

It is an arithmetic number, because the mean of its divisors is an integer number (1487360).

Almost surely, 2^81882780 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81882780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142786560).

81882780 is an abundant number, since it is smaller than the sum of its proper divisors (203690340).

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

81882780 is a wasteful number, since it uses less digits than its factorization.

81882780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400 (or 398 counting only the distinct ones).

The product of its (nonzero) digits is 57344, while the sum is 42.

The square root of 81882780 is about 9048.9104316487. The cubic root of 81882780 is about 434.2410335455.

The spelling of 81882780 in words is "eighty-one million, eight hundred eighty-two thousand, seven hundred eighty".