987211993 has 4 divisors (see below), whose sum is σ = 987928228. Its totient is φ = 986495760.

The previous prime is 987211987. The next prime is 987212011. The reversal of 987211993 is 399112789.

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

It can be written as a sum of positive squares in 2 ways, for example, as 152695449 + 834516544 = 12357^2 + 28888^2 .

It is a cyclic number.

It is not a de Polignac number, because 987211993 - 2¹⁷ = 987080921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (987211943) 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, 356046 + ... + 358807.

It is an arithmetic number, because the mean of its divisors is an integer number (246982057).

Almost surely, 2^987211993 is an apocalyptic number.

It is an amenable number.

987211993 is a deficient number, since it is larger than the sum of its proper divisors (716235).

987211993 is a wasteful number, since it uses less digits than its factorization.

987211993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716234.

The product of its digits is 244944, while the sum is 49.

The square root of 987211993 is about 31419.9298694316. The cubic root of 987211993 is about 995.7190304517.

The spelling of 987211993 in words is "nine hundred eighty-seven million, two hundred eleven thousand, nine hundred ninety-three".