987817951 has 4 divisors (see below), whose sum is σ = 990110304. Its totient is φ = 985525600.

The previous prime is 987817949. The next prime is 987818011. The reversal of 987817951 is 159718789.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 987817951 - 2¹ = 987817949 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 987817892 and 987817901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (987817931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1145530 + ... + 1146391.

It is an arithmetic number, because the mean of its divisors is an integer number (247527576).

Almost surely, 2^987817951 is an apocalyptic number.

987817951 is a deficient number, since it is larger than the sum of its proper divisors (2292353).

987817951 is a wasteful number, since it uses less digits than its factorization.

987817951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2292352.

The product of its digits is 1270080, while the sum is 55.

The square root of 987817951 is about 31429.5712824722. The cubic root of 987817951 is about 995.9227153438.

The spelling of 987817951 in words is "nine hundred eighty-seven million, eight hundred seventeen thousand, nine hundred fifty-one".