123640560 has 80 divisors (see below), whose sum is σ = 425880480. Its totient is φ = 32970240.

The previous prime is 123640547. The next prime is 123640591. The reversal of 123640560 is 65046321.

123640560 is a `hidden beast` number, since 12 + 3 + 640 + 5 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×123640560² = 30573976154227200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26461 + ... + 30780.

It is an arithmetic number, because the mean of its divisors is an integer number (5323506).

Almost surely, 2^123640560 is an apocalyptic number.

123640560 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

123640560 is an abundant number, since it is smaller than the sum of its proper divisors (302239920).

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

123640560 is a wasteful number, since it uses less digits than its factorization.

123640560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57263 (or 57251 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 123640560 is about 11119.3776804280. The cubic root of 123640560 is about 498.1808024010.

Adding to 123640560 its reverse (65046321), we get a palindrome (188686881).

The spelling of 123640560 in words is "one hundred twenty-three million, six hundred forty thousand, five hundred sixty".