87766721 has 16 divisors (see below), whose sum is σ = 102539520. Its totient is φ = 73570560.

The previous prime is 87766711. The next prime is 87766747. The reversal of 87766721 is 12766778.

It is not a de Polignac number, because 87766721 - 2²² = 83572417 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (87766711) 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, 67445 + ... + 68733.

It is an arithmetic number, because the mean of its divisors is an integer number (6408720).

Almost surely, 2^87766721 is an apocalyptic number.

It is an amenable number.

87766721 is a deficient number, since it is larger than the sum of its proper divisors (14772799).

87766721 is a wasteful number, since it uses less digits than its factorization.

87766721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1504.

The product of its digits is 197568, while the sum is 44.

The square root of 87766721 is about 9368.3894560378. The cubic root of 87766721 is about 444.4026340507.

The spelling of 87766721 in words is "eighty-seven million, seven hundred sixty-six thousand, seven hundred twenty-one".