81146261 has 4 divisors (see below), whose sum is σ = 92738592. Its totient is φ = 69553932.

The previous prime is 81146243. The next prime is 81146279. The reversal of 81146261 is 16264118.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (81146243) and next prime (81146279).

It is not a de Polignac number, because 81146261 - 2¹⁸ = 80884117 is a prime.

It is a super-4 number, since 4×81146261⁴ (a number of 33 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81046261) 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, 5796155 + ... + 5796168.

It is an arithmetic number, because the mean of its divisors is an integer number (23184648).

Almost surely, 2^81146261 is an apocalyptic number.

It is an amenable number.

81146261 is a deficient number, since it is larger than the sum of its proper divisors (11592331).

81146261 is a wasteful number, since it uses less digits than its factorization.

81146261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11592330.

The product of its digits is 2304, while the sum is 29.

The square root of 81146261 is about 9008.1219463327. The cubic root of 81146261 is about 432.9351402583.

The spelling of 81146261 in words is "eighty-one million, one hundred forty-six thousand, two hundred sixty-one".