81404653 has 24 divisors (see below), whose sum is σ = 97699680. Its totient is φ = 67173120.

The previous prime is 81404647. The next prime is 81404663. The reversal of 81404653 is 35640418.

It is a happy number.

It is not a de Polignac number, because 81404653 - 2⁵ = 81404621 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81404623) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 91750 + ... + 92632.

It is an arithmetic number, because the mean of its divisors is an integer number (4070820).

Almost surely, 2^81404653 is an apocalyptic number.

It is an amenable number.

81404653 is a deficient number, since it is larger than the sum of its proper divisors (16295027).

81404653 is a wasteful number, since it uses less digits than its factorization.

81404653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 957 (or 940 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 81404653 is about 9022.4527153097. The cubic root of 81404653 is about 433.3941815277.

The spelling of 81404653 in words is "eighty-one million, four hundred four thousand, six hundred fifty-three".