81225670 has 16 divisors (see below), whose sum is σ = 146340288. Its totient is φ = 32460480.

The previous prime is 81225659. The next prime is 81225679. The reversal of 81225670 is 7652218.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81225679) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10210 + ... + 16330.

It is an arithmetic number, because the mean of its divisors is an integer number (9146268).

Almost surely, 2^81225670 is an apocalyptic number.

81225670 is a deficient number, since it is larger than the sum of its proper divisors (65114618).

81225670 is a wasteful number, since it uses less digits than its factorization.

81225670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7455.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 81225670 is about 9012.5285020354. The cubic root of 81225670 is about 433.0763163598.

Adding to 81225670 its reverse (7652218), we get a palindrome (88877888).

The spelling of 81225670 in words is "eighty-one million, two hundred twenty-five thousand, six hundred seventy".