81982901 has 16 divisors (see below), whose sum is σ = 110076288. Its totient is φ = 58968000.

The previous prime is 81982889. The next prime is 81982907. The reversal of 81982901 is 10928918.

It is not a de Polignac number, because 81982901 - 2¹⁸ = 81720757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81982907) 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, 39950 + ... + 41951.

It is an arithmetic number, because the mean of its divisors is an integer number (6879768).

Almost surely, 2^81982901 is an apocalyptic number.

It is an amenable number.

81982901 is a deficient number, since it is larger than the sum of its proper divisors (28093387).

81982901 is a wasteful number, since it uses less digits than its factorization.

81982901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81932.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 81982901 is about 9054.4409545813. The cubic root of 81982901 is about 434.4179487992.

The spelling of 81982901 in words is "eighty-one million, nine hundred eighty-two thousand, nine hundred one".