123121530 has 192 divisors, whose sum is σ = 396264960. Its totient is φ = 25901568.

The previous prime is 123121519. The next prime is 123121543. The reversal of 123121530 is 35121321.

123121530 is a `hidden beast` number, since 12 + 3 + 121 + 530 = 666.

It is a super-2 number, since 2×123121530² = 30317822299081800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 420064 + ... + 420356.

It is an arithmetic number, because the mean of its divisors is an integer number (2063880).

Almost surely, 2^123121530 is an apocalyptic number.

123121530 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 123121530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (198132480).

123121530 is an abundant number, since it is smaller than the sum of its proper divisors (273143430).

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

123121530 is a wasteful number, since it uses less digits than its factorization.

123121530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365 (or 362 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 123121530 is about 11096.0141492339. The cubic root of 123121530 is about 497.4827212167.

Adding to 123121530 its reverse (35121321), we get a palindrome (158242851).

The spelling of 123121530 in words is "one hundred twenty-three million, one hundred twenty-one thousand, five hundred thirty".