81602140 has 48 divisors (see below), whose sum is σ = 175551264. Its totient is φ = 31852800.

The previous prime is 81602117. The next prime is 81602153. The reversal of 81602140 is 4120618.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 257262 + ... + 257578.

It is an arithmetic number, because the mean of its divisors is an integer number (3657318).

Almost surely, 2^81602140 is an apocalyptic number.

It is an amenable number.

81602140 is an abundant number, since it is smaller than the sum of its proper divisors (93949124).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81602140 is a wasteful number, since it uses less digits than its factorization.

81602140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 598 (or 596 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 81602140 is about 9033.3902827233. The cubic root of 81602140 is about 433.7443687033.

Adding to 81602140 its reverse (4120618), we get a palindrome (85722758).

The spelling of 81602140 in words is "eighty-one million, six hundred two thousand, one hundred forty".