81526601 has 8 divisors (see below), whose sum is σ = 87973704. Its totient is φ = 75104640.

The previous prime is 81526591. The next prime is 81526603. The reversal of 81526601 is 10662518.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5400976 + 76125625 = 2324^2 + 8725^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-81526601 is a prime.

It is a super-2 number, since 2×81526601² = 13293173341226402, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81526603) 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, 755 + ... + 12791.

It is an arithmetic number, because the mean of its divisors is an integer number (10996713).

Almost surely, 2^81526601 is an apocalyptic number.

It is an amenable number.

81526601 is a deficient number, since it is larger than the sum of its proper divisors (6447103).

81526601 is a wasteful number, since it uses less digits than its factorization.

81526601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12571.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 81526601 is about 9029.2082155635. The cubic root of 81526601 is about 433.6104885088.

The spelling of 81526601 in words is "eighty-one million, five hundred twenty-six thousand, six hundred one".