81602653 has 4 divisors (see below), whose sum is σ = 89021088. Its totient is φ = 74184220.

The previous prime is 81602639. The next prime is 81602671. The reversal of 81602653 is 35620618.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 81602653 - 2¹⁷ = 81471581 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81602603) 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, 3709201 + ... + 3709222.

It is an arithmetic number, because the mean of its divisors is an integer number (22255272).

Almost surely, 2^81602653 is an apocalyptic number.

It is an amenable number.

81602653 is a deficient number, since it is larger than the sum of its proper divisors (7418435).

81602653 is a wasteful number, since it uses less digits than its factorization.

81602653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7418434.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 81602653 is about 9033.4186773336. The cubic root of 81602653 is about 433.7452776272.

The spelling of 81602653 in words is "eighty-one million, six hundred two thousand, six hundred fifty-three".