81547461266 has 8 divisors (see below), whose sum is σ = 122327293500. Its totient is φ = 40771696768.

The previous prime is 81547461263. The next prime is 81547461287. The reversal of 81547461266 is 66216474518.

It can be written as a sum of positive squares in 2 ways, for example, as 75723482041 + 5823979225 = 275179^2 + 76315^2 .

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

It is not an unprimeable number, because it can be changed into a prime (81547461263) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 966311 + ... + 1047306.

Almost surely, 2^81547461266 is an apocalyptic number.

81547461266 is a deficient number, since it is larger than the sum of its proper divisors (40779832234).

81547461266 is a wasteful number, since it uses less digits than its factorization.

81547461266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2033868.

The product of its digits is 1935360, while the sum is 50.

The spelling of 81547461266 in words is "eighty-one billion, five hundred forty-seven million, four hundred sixty-one thousand, two hundred sixty-six".