81222910 has 32 divisors (see below), whose sum is σ = 159213600. Its totient is φ = 29715840.

The previous prime is 81222893. The next prime is 81222917. The reversal of 81222910 is 1922218.

It is a super-2 number, since 2×81222910² = 13194322217736200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81222917) 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, 1861 + ... + 12880.

It is an arithmetic number, because the mean of its divisors is an integer number (4975425).

Almost surely, 2^81222910 is an apocalyptic number.

81222910 is a deficient number, since it is larger than the sum of its proper divisors (77990690).

81222910 is a wasteful number, since it uses less digits than its factorization.

81222910 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14796.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 81222910 is about 9012.3753805531. The cubic root of 81222910 is about 433.0714110789.

The spelling of 81222910 in words is "eighty-one million, two hundred twenty-two thousand, nine hundred ten".