81883787 has 4 divisors (see below), whose sum is σ = 86193480. Its totient is φ = 77574096.

The previous prime is 81883771. The next prime is 81883793. The reversal of 81883787 is 78738818.

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

It is a cyclic number.

It is not a de Polignac number, because 81883787 - 2⁴ = 81883771 is a prime.

It is a super-2 number, since 2×81883787² = 13409909146922738, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81883717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2154818 + ... + 2154855.

It is an arithmetic number, because the mean of its divisors is an integer number (21548370).

Almost surely, 2^81883787 is an apocalyptic number.

81883787 is a deficient number, since it is larger than the sum of its proper divisors (4309693).

81883787 is a wasteful number, since it uses less digits than its factorization.

81883787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4309692.

The product of its digits is 602112, while the sum is 50.

The square root of 81883787 is about 9048.9660735357. The cubic root of 81883787 is about 434.2428136468.

The spelling of 81883787 in words is "eighty-one million, eight hundred eighty-three thousand, seven hundred eighty-seven".