81867772070 has 16 divisors (see below), whose sum is σ = 168413702688. Its totient is φ = 28068950400.

The previous prime is 81867772061. The next prime is 81867772079. The reversal of 81867772070 is 7027776818.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81867772061) and next prime (81867772079).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81867772079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 584769731 + ... + 584769870.

It is an arithmetic number, because the mean of its divisors is an integer number (10525856418).

Almost surely, 2^81867772070 is an apocalyptic number.

81867772070 is an abundant number, since it is smaller than the sum of its proper divisors (86545930618).

81867772070 is a wasteful number, since it uses less digits than its factorization.

81867772070 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1169539615.

The product of its (nonzero) digits is 1843968, while the sum is 53.

The spelling of 81867772070 in words is "eighty-one billion, eight hundred sixty-seven million, seven hundred seventy-two thousand, seventy".