987690781 has 16 divisors (see below), whose sum is σ = 1233671040. Its totient is φ = 768214080.

The previous prime is 987690757. The next prime is 987690827. The reversal of 987690781 is 187096789.

It is a cyclic number.

It is not a de Polignac number, because 987690781 - 2⁷ = 987690653 is a prime.

It is a super-2 number, since 2×987690781² = 1951066157744779922, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (987690481) 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, 31375 + ... + 54403.

It is an arithmetic number, because the mean of its divisors is an integer number (77104440).

Almost surely, 2^987690781 is an apocalyptic number.

It is an amenable number.

987690781 is a deficient number, since it is larger than the sum of its proper divisors (245980259).

987690781 is a wasteful number, since it uses less digits than its factorization.

987690781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23604.

The product of its (nonzero) digits is 1524096, while the sum is 55.

The square root of 987690781 is about 31427.5481226264. The cubic root of 987690781 is about 995.8799757118.

The spelling of 987690781 in words is "nine hundred eighty-seven million, six hundred ninety thousand, seven hundred eighty-one".