81687266098 has 4 divisors (see below), whose sum is σ = 122530899150. Its totient is φ = 40843633048.

The previous prime is 81687266077. The next prime is 81687266119. The reversal of 81687266098 is 89066278618.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 89066278618 = 2 ⋅44533139309.

It is an interprime number because it is at equal distance from previous prime (81687266077) and next prime (81687266119).

It can be written as a sum of positive squares in only one way, i.e., 65970381409 + 15716884689 = 256847^2 + 125367^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20421816523 + ... + 20421816526.

Almost surely, 2^81687266098 is an apocalyptic number.

81687266098 is a deficient number, since it is larger than the sum of its proper divisors (40843633052).

81687266098 is a wasteful number, since it uses less digits than its factorization.

81687266098 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40843633051.

The product of its (nonzero) digits is 13934592, while the sum is 61.

The spelling of 81687266098 in words is "eighty-one billion, six hundred eighty-seven million, two hundred sixty-six thousand, ninety-eight".