999688387 has 2 divisors, whose sum is σ = 999688388. Its totient is φ = 999688386.

The previous prime is 999688373. The next prime is 999688427. The reversal of 999688387 is 783886999.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 999688387 - 2⁷ = 999688259 is a prime.

It is a super-2 number, since 2×999688387² = 1998753742205323538, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (999688337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499844193 + 499844194.

It is an arithmetic number, because the mean of its divisors is an integer number (499844194).

Almost surely, 2^999688387 is an apocalyptic number.

999688387 is a deficient number, since it is larger than the sum of its proper divisors (1).

999688387 is an equidigital number, since it uses as much as digits as its factorization.

999688387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 47029248, while the sum is 67.

The square root of 999688387 is about 31617.8491836494. The cubic root of 999688387 is about 999.8961182089.

The spelling of 999688387 in words is "nine hundred ninety-nine million, six hundred eighty-eight thousand, three hundred eighty-seven".