123021690 has 64 divisors (see below), whose sum is σ = 341055360. Its totient is φ = 28067840.

The previous prime is 123021649. The next prime is 123021697. The reversal of 123021690 is 96120321.

It is a super-2 number, since 2×123021690² = 30268672420912200, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 123021690.

It is not an unprimeable number, because it can be changed into a prime (123021697) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5355 + ... + 16574.

It is an arithmetic number, because the mean of its divisors is an integer number (5328990).

Almost surely, 2^123021690 is an apocalyptic number.

123021690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

123021690 is an abundant number, since it is smaller than the sum of its proper divisors (218033670).

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

123021690 is a wasteful number, since it uses less digits than its factorization.

123021690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21967.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 123021690 is about 11091.5143240227. The cubic root of 123021690 is about 497.3482142612.

The spelling of 123021690 in words is "one hundred twenty-three million, twenty-one thousand, six hundred ninety".