128419987 has 8 divisors (see below), whose sum is σ = 129691136. Its totient is φ = 127153152.

The previous prime is 128419979. The next prime is 128420041. The reversal of 128419987 is 789914821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128419987 - 2³ = 128419979 is a prime.

It is a super-2 number, since 2×128419987² = 32983386122160338, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128419987.

It is not an unprimeable number, because it can be changed into a prime (128419927) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 110803 + ... + 111955.

It is an arithmetic number, because the mean of its divisors is an integer number (16211392).

Almost surely, 2^128419987 is an apocalyptic number.

128419987 is a deficient number, since it is larger than the sum of its proper divisors (1271149).

128419987 is a wasteful number, since it uses less digits than its factorization.

128419987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2157.

The product of its digits is 290304, while the sum is 49.

The square root of 128419987 is about 11332.2542770624. The cubic root of 128419987 is about 504.5190165978.

The spelling of 128419987 in words is "one hundred twenty-eight million, four hundred nineteen thousand, nine hundred eighty-seven".