81901738 has 8 divisors (see below), whose sum is σ = 124686432. Its totient is φ = 40339596.

The previous prime is 81901717. The next prime is 81901739. The reversal of 81901738 is 83710918.

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

It is a junction number, because it is equal to n+sod(n) for n = 81901697 and 81901706.

It is not an unprimeable number, because it can be changed into a prime (81901739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 305470 + ... + 305737.

It is an arithmetic number, because the mean of its divisors is an integer number (15585804).

Almost surely, 2^81901738 is an apocalyptic number.

81901738 is a deficient number, since it is larger than the sum of its proper divisors (42784694).

81901738 is a wasteful number, since it uses less digits than its factorization.

81901738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611276.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 81901738 is about 9049.9579004546. The cubic root of 81901738 is about 434.2745436692.

The spelling of 81901738 in words is "eighty-one million, nine hundred one thousand, seven hundred thirty-eight".