81202901 has 16 divisors (see below), whose sum is σ = 90250608. Its totient is φ = 72576000.

The previous prime is 81202883. The next prime is 81202907. The reversal of 81202901 is 10920218.

It can be written as a sum of positive squares in 8 ways, for example, as 22801 + 81180100 = 151^2 + 9010^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81202901 is a prime.

It is a super-2 number, since 2×81202901² = 13187822261631602, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81202907) 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, 192671 + ... + 193091.

It is an arithmetic number, because the mean of its divisors is an integer number (5640663).

Almost surely, 2^81202901 is an apocalyptic number.

It is an amenable number.

81202901 is a deficient number, since it is larger than the sum of its proper divisors (9047707).

81202901 is a wasteful number, since it uses less digits than its factorization.

81202901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 872.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 81202901 is about 9011.2652274805. The cubic root of 81202901 is about 433.0358462466.

The spelling of 81202901 in words is "eighty-one million, two hundred two thousand, nine hundred one".