81652389 has 32 divisors (see below), whose sum is σ = 134534400. Its totient is φ = 42895872.

The previous prime is 81652381. The next prime is 81652391. The reversal of 81652389 is 98325618.

It is not a de Polignac number, because 81652389 - 2³ = 81652381 is a prime.

It is a super-2 number, since 2×81652389² = 13334225258814642, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 81652389.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81652381) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 94849 + ... + 95705.

It is an arithmetic number, because the mean of its divisors is an integer number (4204200).

Almost surely, 2^81652389 is an apocalyptic number.

It is an amenable number.

81652389 is a deficient number, since it is larger than the sum of its proper divisors (52882011).

81652389 is a wasteful number, since it uses less digits than its factorization.

81652389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1229.

The product of its digits is 103680, while the sum is 42.

The square root of 81652389 is about 9036.1711471176. The cubic root of 81652389 is about 433.8333808649.

The spelling of 81652389 in words is "eighty-one million, six hundred fifty-two thousand, three hundred eighty-nine".