81606509282 has 4 divisors (see below), whose sum is σ = 122409763926. Its totient is φ = 40803254640.

The previous prime is 81606509273. The next prime is 81606509291. The reversal of 81606509282 is 28290560618.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (81606509273) and next prime (81606509291).

It can be written as a sum of positive squares in only one way, i.e., 75976858321 + 5629650961 = 275639^2 + 75031^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20401627319 + ... + 20401627322.

Almost surely, 2^81606509282 is an apocalyptic number.

81606509282 is a deficient number, since it is larger than the sum of its proper divisors (40803254644).

81606509282 is a wasteful number, since it uses less digits than its factorization.

81606509282 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40803254643.

The product of its (nonzero) digits is 414720, while the sum is 47.

The spelling of 81606509282 in words is "eighty-one billion, six hundred six million, five hundred nine thousand, two hundred eighty-two".