999980687 has 4 divisors (see below), whose sum is σ = 1000044696. Its totient is φ = 999916680.

The previous prime is 999980677. The next prime is 999980689. The reversal of 999980687 is 786089999.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 786089999 = 199 ⋅3950201.

It is a cyclic number.

It is not a de Polignac number, because 999980687 - 2⁶ = 999980623 is a prime.

It is a super-2 number, since 2×999980687² = 1999922748745983938, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999980689) 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, 8612 + ... + 45542.

It is an arithmetic number, because the mean of its divisors is an integer number (250011174).

Almost surely, 2^999980687 is an apocalyptic number.

999980687 is a deficient number, since it is larger than the sum of its proper divisors (64009).

999980687 is a wasteful number, since it uses less digits than its factorization.

999980687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64008.

The product of its (nonzero) digits is 17635968, while the sum is 65.

The square root of 999980687 is about 31622.4712348671. The cubic root of 999980687 is about 999.9935622919.

The spelling of 999980687 in words is "nine hundred ninety-nine million, nine hundred eighty thousand, six hundred eighty-seven".