123400561635 has 48 divisors (see below), whose sum is σ = 231439641888. Its totient is φ = 60463065600.

The previous prime is 123400561601. The next prime is 123400561651. The reversal of 123400561635 is 536165004321.

123400561635 is a `hidden beast` number, since 1 + 2 + 3 + 4 + 0 + 0 + 5 + 616 + 35 = 666.

It is not a de Polignac number, because 123400561635 - 2²⁶ = 123333452771 is a prime.

It is a super-2 number, since 2×123400561635² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 123400561635.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 376426 + ... + 623295.

It is an arithmetic number, because the mean of its divisors is an integer number (4821659206).

Almost surely, 2^123400561635 is an apocalyptic number.

123400561635 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

123400561635 is a deficient number, since it is larger than the sum of its proper divisors (108039080253).

123400561635 is a wasteful number, since it uses less digits than its factorization.

123400561635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 999956 (or 999953 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

Adding to 123400561635 its reverse (536165004321), we get a palindrome (659565565956).

It can be divided in two parts, 123400 and 561635, that added together give a triangular number (685035 = T₁₁₇₀).

The spelling of 123400561635 in words is "one hundred twenty-three billion, four hundred million, five hundred sixty-one thousand, six hundred thirty-five".