81653830 has 32 divisors (see below), whose sum is σ = 155266560. Its totient is φ = 30831840.

The previous prime is 81653827. The next prime is 81653833. The reversal of 81653830 is 3835618.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81653827) and next prime (81653833).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81653833) 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, 69145 + ... + 70315.

It is an arithmetic number, because the mean of its divisors is an integer number (4852080).

Almost surely, 2^81653830 is an apocalyptic number.

81653830 is a deficient number, since it is larger than the sum of its proper divisors (73612730).

81653830 is a wasteful number, since it uses less digits than its factorization.

81653830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1564.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 81653830 is about 9036.2508818647. The cubic root of 81653830 is about 433.8359329447.

The spelling of 81653830 in words is "eighty-one million, six hundred fifty-three thousand, eight hundred thirty".