81742213 has 16 divisors (see below), whose sum is σ = 99262080. Its totient is φ = 65814336.

The previous prime is 81742201. The next prime is 81742223. The reversal of 81742213 is 31224718.

It is not a de Polignac number, because 81742213 - 2⁵ = 81742181 is a prime.

It is a super-2 number, since 2×81742213² = 13363578772274738, which contains 22 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 (81742223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2070 + ... + 12952.

It is an arithmetic number, because the mean of its divisors is an integer number (6203880).

Almost surely, 2^81742213 is an apocalyptic number.

It is an amenable number.

81742213 is a deficient number, since it is larger than the sum of its proper divisors (17519867).

81742213 is a wasteful number, since it uses less digits than its factorization.

81742213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10956.

The product of its digits is 2688, while the sum is 28.

The square root of 81742213 is about 9041.1400276735. The cubic root of 81742213 is about 433.9924060908.

The spelling of 81742213 in words is "eighty-one million, seven hundred forty-two thousand, two hundred thirteen".