81870133 has 4 divisors (see below), whose sum is σ = 85429728. Its totient is φ = 78310540.

The previous prime is 81870127. The next prime is 81870197. The reversal of 81870133 is 33107818.

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 a cyclic number.

It is not a de Polignac number, because 81870133 - 2⁹ = 81869621 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81870095 and 81870104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81810133) 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, 1779763 + ... + 1779808.

It is an arithmetic number, because the mean of its divisors is an integer number (21357432).

Almost surely, 2^81870133 is an apocalyptic number.

It is an amenable number.

81870133 is a deficient number, since it is larger than the sum of its proper divisors (3559595).

81870133 is a wasteful number, since it uses less digits than its factorization.

81870133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3559594.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 81870133 is about 9048.2115912483. The cubic root of 81870133 is about 434.2186758568.

The spelling of 81870133 in words is "eighty-one million, eight hundred seventy thousand, one hundred thirty-three".