123537654021 has 4 divisors (see below), whose sum is σ = 164716872032. Its totient is φ = 82358436012.

The previous prime is 123537654017. The next prime is 123537654043. The reversal of 123537654021 is 120456735321.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 123537654021 - 2² = 123537654017 is a prime.

It is a super-2 number, since 2×123537654021² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123537654001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20589609001 + ... + 20589609006.

It is an arithmetic number, because the mean of its divisors is an integer number (41179218008).

Almost surely, 2^123537654021 is an apocalyptic number.

It is an amenable number.

123537654021 is a deficient number, since it is larger than the sum of its proper divisors (41179218011).

123537654021 is an equidigital number, since it uses as much as digits as its factorization.

123537654021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41179218010.

The product of its (nonzero) digits is 151200, while the sum is 39.

The spelling of 123537654021 in words is "one hundred twenty-three billion, five hundred thirty-seven million, six hundred fifty-four thousand, twenty-one".