81887751345 has 16 divisors (see below), whose sum is σ = 136716941952. Its totient is φ = 41774620800.

The previous prime is 81887751343. The next prime is 81887751347. The reversal of 81887751345 is 54315778818.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81887751343) and next prime (81887751347).

It is not a de Polignac number, because 81887751345 - 2¹ = 81887751343 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81887751343) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 118677556 + ... + 118678245.

It is an arithmetic number, because the mean of its divisors is an integer number (8544808872).

Almost surely, 2^81887751345 is an apocalyptic number.

It is an amenable number.

81887751345 is a deficient number, since it is larger than the sum of its proper divisors (54829190607).

81887751345 is a wasteful number, since it uses less digits than its factorization.

81887751345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237355832.

The product of its digits is 7526400, while the sum is 57.

The spelling of 81887751345 in words is "eighty-one billion, eight hundred eighty-seven million, seven hundred fifty-one thousand, three hundred forty-five".