81906850 has 48 divisors (see below), whose sum is σ = 162532008. Its totient is φ = 30602240.

The previous prime is 81906823. The next prime is 81906857. The reversal of 81906850 is 5860918.

It can be written as a sum of positive squares in 12 ways, for example, as 12201049 + 69705801 = 3493^2 + 8349^2 .

It is a super-3 number, since 3×81906850³ (a number of 25 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (81906857) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 146772 + ... + 147328.

Almost surely, 2^81906850 is an apocalyptic number.

81906850 is a deficient number, since it is larger than the sum of its proper divisors (80625158).

81906850 is a wasteful number, since it uses less digits than its factorization.

81906850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 759 (or 754 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 37.

The square root of 81906850 is about 9050.2403283007. The cubic root of 81906850 is about 434.2835787452.

The spelling of 81906850 in words is "eighty-one million, nine hundred six thousand, eight hundred fifty".