87781691 has 8 divisors (see below), whose sum is σ = 92766480. Its totient is φ = 82833408.

The previous prime is 87781669. The next prime is 87781703. The reversal of 87781691 is 19618778.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 87781691 - 2⁶ = 87781627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87781601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4106 + ... + 13871.

It is an arithmetic number, because the mean of its divisors is an integer number (11595810).

Almost surely, 2^87781691 is an apocalyptic number.

87781691 is a deficient number, since it is larger than the sum of its proper divisors (4984789).

87781691 is a wasteful number, since it uses less digits than its factorization.

87781691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18253.

The product of its digits is 169344, while the sum is 47.

The square root of 87781691 is about 9369.1883853405. The cubic root of 87781691 is about 444.4278992429.

The spelling of 87781691 in words is "eighty-seven million, seven hundred eighty-one thousand, six hundred ninety-one".