128922990 has 64 divisors (see below), whose sum is σ = 355332096. Its totient is φ = 29325312.

The previous prime is 128922979. The next prime is 128923001. The reversal of 128922990 is 99229821.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (128922979) and next prime (128923001).

It is a super-2 number, since 2×128922990² = 33242274701080200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

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, 45454 + ... + 48206.

It is an arithmetic number, because the mean of its divisors is an integer number (5552064).

Almost surely, 2^128922990 is an apocalyptic number.

128922990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 128922990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (177666048).

128922990 is an abundant number, since it is smaller than the sum of its proper divisors (226409106).

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

128922990 is a wasteful number, since it uses less digits than its factorization.

128922990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2993.

The product of its (nonzero) digits is 46656, while the sum is 42.

The square root of 128922990 is about 11354.4260092706. The cubic root of 128922990 is about 505.1768684137.

The spelling of 128922990 in words is "one hundred twenty-eight million, nine hundred twenty-two thousand, nine hundred ninety".