87331781 has 8 divisors (see below), whose sum is σ = 90013440. Its totient is φ = 84684528.

The previous prime is 87331723. The next prime is 87331787. The reversal of 87331781 is 18713378.

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 87331781 - 2²² = 83137477 is a prime.

It is a super-2 number, since 2×87331781² = 15253679945263922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87331787) 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 7 ways as a sum of consecutive naturals, for example, 3401 + ... + 13646.

It is an arithmetic number, because the mean of its divisors is an integer number (11251680).

Almost surely, 2^87331781 is an apocalyptic number.

It is an amenable number.

87331781 is a deficient number, since it is larger than the sum of its proper divisors (2681659).

87331781 is a wasteful number, since it uses less digits than its factorization.

87331781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17203.

The product of its digits is 28224, while the sum is 38.

The square root of 87331781 is about 9345.1474573706. The cubic root of 87331781 is about 443.6673186958.

The spelling of 87331781 in words is "eighty-seven million, three hundred thirty-one thousand, seven hundred eighty-one".