128878890 has 64 divisors (see below), whose sum is σ = 368879616. Its totient is φ = 28176192.

The previous prime is 128878877. The next prime is 128878903. The reversal of 128878890 is 98878821.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (128878877) and next prime (128878903).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8512 + ... + 18171.

It is an arithmetic number, because the mean of its divisors is an integer number (5763744).

Almost surely, 2^128878890 is an apocalyptic number.

128878890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

128878890 is an abundant number, since it is smaller than the sum of its proper divisors (240000726).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128878890 is a wasteful number, since it uses less digits than its factorization.

128878890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26723.

The product of its (nonzero) digits is 516096, while the sum is 51.

The square root of 128878890 is about 11352.4838691803. The cubic root of 128878890 is about 505.1192607918.

The spelling of 128878890 in words is "one hundred twenty-eight million, eight hundred seventy-eight thousand, eight hundred ninety".