81652641 has 16 divisors (see below), whose sum is σ = 124637184. Its totient is φ = 46578384.

The previous prime is 81652621. The next prime is 81652643. The reversal of 81652641 is 14625618.

It is not a de Polignac number, because 81652641 - 2⁶ = 81652577 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81652643) 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, 10480 + ... + 16526.

It is an arithmetic number, because the mean of its divisors is an integer number (7789824).

Almost surely, 2^81652641 is an apocalyptic number.

It is an amenable number.

81652641 is a deficient number, since it is larger than the sum of its proper divisors (42984543).

81652641 is a wasteful number, since it uses less digits than its factorization.

81652641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6700.

The product of its digits is 11520, while the sum is 33.

The square root of 81652641 is about 9036.1850910658. The cubic root of 81652641 is about 433.8338271711.

The spelling of 81652641 in words is "eighty-one million, six hundred fifty-two thousand, six hundred forty-one".