81780734 has 8 divisors (see below), whose sum is σ = 140195568. Its totient is φ = 35048880.

The previous prime is 81780719. The next prime is 81780757. The reversal of 81780734 is 43708718.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2920727 + ... + 2920754.

It is an arithmetic number, because the mean of its divisors is an integer number (17524446).

Almost surely, 2^81780734 is an apocalyptic number.

81780734 is a deficient number, since it is larger than the sum of its proper divisors (58414834).

81780734 is a wasteful number, since it uses less digits than its factorization.

81780734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5841490.

The product of its (nonzero) digits is 37632, while the sum is 38.

The square root of 81780734 is about 9043.2700943851. The cubic root of 81780734 is about 434.0605683269.

The spelling of 81780734 in words is "eighty-one million, seven hundred eighty thousand, seven hundred thirty-four".