81741956 has 6 divisors (see below), whose sum is σ = 143048430. Its totient is φ = 40870976.

The previous prime is 81741949. The next prime is 81741973. The reversal of 81741956 is 65914718.

It can be written as a sum of positive squares in only one way, i.e., 41165056 + 40576900 = 6416^2 + 6370^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10217741 + ... + 10217748.

It is an arithmetic number, because the mean of its divisors is an integer number (23841405).

Almost surely, 2^81741956 is an apocalyptic number.

It is an amenable number.

81741956 is a deficient number, since it is larger than the sum of its proper divisors (61306474).

81741956 is a wasteful number, since it uses less digits than its factorization.

81741956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20435493 (or 20435491 counting only the distinct ones).

The product of its digits is 60480, while the sum is 41.

The square root of 81741956 is about 9041.1258148529. The cubic root of 81741956 is about 433.9919512619.

The spelling of 81741956 in words is "eighty-one million, seven hundred forty-one thousand, nine hundred fifty-six".