8161581788 has 6 divisors (see below), whose sum is σ = 14282768136. Its totient is φ = 4080790892.

The previous prime is 8161581787. The next prime is 8161581793. The reversal of 8161581788 is 8871851618.

It is a super-2 number, since 2×8161581788² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8161581787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1020197720 + ... + 1020197727.

It is an arithmetic number, because the mean of its divisors is an integer number (2380461356).

Almost surely, 2^8161581788 is an apocalyptic number.

It is an amenable number.

8161581788 is a deficient number, since it is larger than the sum of its proper divisors (6121186348).

8161581788 is a wasteful number, since it uses less digits than its factorization.

8161581788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2040395451 (or 2040395449 counting only the distinct ones).

The product of its digits is 860160, while the sum is 53.

The square root of 8161581788 is about 90341.4732445736. The cubic root of 8161581788 is about 2013.3754976209.

The spelling of 8161581788 in words is "eight billion, one hundred sixty-one million, five hundred eighty-one thousand, seven hundred eighty-eight".