81357222 has 16 divisors (see below), whose sum is σ = 163006272. Its totient is φ = 27070440.

The previous prime is 81357193. The next prime is 81357251. The reversal of 81357222 is 22275318.

It is an interprime number because it is at equal distance from previous prime (81357193) and next prime (81357251).

It is a self number, because there is not a number n which added to its sum of digits gives 81357222.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8448 + ... + 15299.

It is an arithmetic number, because the mean of its divisors is an integer number (10187892).

Almost surely, 2^81357222 is an apocalyptic number.

81357222 is an abundant number, since it is smaller than the sum of its proper divisors (81649050).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81357222 is a wasteful number, since it uses less digits than its factorization.

81357222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24323.

The product of its digits is 6720, while the sum is 30.

The square root of 81357222 is about 9019.8238341999. The cubic root of 81357222 is about 433.3099917736.

The spelling of 81357222 in words is "eighty-one million, three hundred fifty-seven thousand, two hundred twenty-two".