81961078 has 8 divisors (see below), whose sum is σ = 124498080. Its totient is φ = 40461720.

The previous prime is 81961043. The next prime is 81961081. The reversal of 81961078 is 87016918.

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

It is a self number, because there is not a number n which added to its sum of digits gives 81961078.

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, 259213 + ... + 259528.

It is an arithmetic number, because the mean of its divisors is an integer number (15562260).

Almost surely, 2^81961078 is an apocalyptic number.

81961078 is a deficient number, since it is larger than the sum of its proper divisors (42537002).

81961078 is a wasteful number, since it uses less digits than its factorization.

81961078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 518822.

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 81961078 is about 9053.2357751248. The cubic root of 81961078 is about 434.3793995241.

The spelling of 81961078 in words is "eighty-one million, nine hundred sixty-one thousand, seventy-eight".