100390987 has 4 divisors (see below), whose sum is σ = 101766280. Its totient is φ = 99015696.

The previous prime is 100390973. The next prime is 100390999. The reversal of 100390987 is 789093001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 789093001 = 79 ⋅9988519.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-100390987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100490987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 687537 + ... + 687682.

It is an arithmetic number, because the mean of its divisors is an integer number (25441570).

Almost surely, 2^100390987 is an apocalyptic number.

100390987 is a deficient number, since it is larger than the sum of its proper divisors (1375293).

100390987 is an equidigital number, since it uses as much as digits as its factorization.

100390987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1375292.

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 100390987 is about 10019.5302784113. The cubic root of 100390987 is about 464.7630302965.

The spelling of 100390987 in words is "one hundred million, three hundred ninety thousand, nine hundred eighty-seven".