7087787721 has 81 divisors (see below), whose sum is σ = 12629065293.
Its totient is φ = 3818813040.
The previous prime is 7087787689. The next prime is 7087787731. The reversal of 7087787721 is 1277877807.
The square root of 7087787721 is 84189.
It is a perfect power (a square), and thus also a powerful number.
It is not a de Polignac number, because 7087787721 - 25 = 7087787689 is a prime.
It is not an unprimeable number, because it can be changed into a prime (7087787731) by changing a digit.
It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 33591306 + ... + 33591516.
Almost surely, 27087787721 is an apocalyptic number.
7087787721 is the 84189-th square number.
7087787721 is the 42095-th centered octagonal number.
It is an amenable number.
7087787721 is a deficient number, since it is larger than the sum of its proper divisors (5541277572).
7087787721 is a wasteful number, since it uses less digits than its factorization.
7087787721 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 480 (or 240 counting only the distinct ones).
The product of its (nonzero) digits is 2151296, while the sum is 54.
The cubic root of 7087787721 is about 1920.8947400408.
The spelling of 7087787721 in words is "seven billion, eighty-seven million, seven hundred eighty-seven thousand, seven hundred twenty-one".