81223007 has 4 divisors (see below), whose sum is σ = 83843136. Its totient is φ = 78602880.

The previous prime is 81222983. The next prime is 81223031. The reversal of 81223007 is 70032218.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 70032218 = 2 ⋅35016109.

It is an interprime number because it is at equal distance from previous prime (81222983) and next prime (81223031).

It is a cyclic number.

It is not a de Polignac number, because 81223007 - 2¹⁰ = 81221983 is a prime.

It is a super-2 number, since 2×81223007² = 13194353732244098, 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 (81223057) 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, 1310018 + ... + 1310079.

It is an arithmetic number, because the mean of its divisors is an integer number (20960784).

Almost surely, 2^81223007 is an apocalyptic number.

81223007 is a deficient number, since it is larger than the sum of its proper divisors (2620129).

81223007 is a wasteful number, since it uses less digits than its factorization.

81223007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2620128.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 81223007 is about 9012.3807620406. The cubic root of 81223007 is about 433.0715834766.

The spelling of 81223007 in words is "eighty-one million, two hundred twenty-three thousand, seven".