81734940 has 144 divisors (see below), whose sum is σ = 295898400. Its totient is φ = 18676224.

The previous prime is 81734911. The next prime is 81734951. The reversal of 81734940 is 4943718.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 81734895 and 81734904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 24916 + ... + 28004.

It is an arithmetic number, because the mean of its divisors is an integer number (2054850).

Almost surely, 2^81734940 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 81734940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147949200).

81734940 is an abundant number, since it is smaller than the sum of its proper divisors (214163460).

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

81734940 is a wasteful number, since it uses less digits than its factorization.

81734940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3121 (or 3106 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 81734940 is about 9040.7378017505. The cubic root of 81734940 is about 433.9795342413.

The spelling of 81734940 in words is "eighty-one million, seven hundred thirty-four thousand, nine hundred forty".