55123123421 has 8 divisors (see below), whose sum is σ = 56185519224. Its totient is φ = 54065848320.

The previous prime is 55123123417. The next prime is 55123123423. The reversal of 55123123421 is 12432132155.

It can be written as a sum of positive squares in 4 ways, for example, as 8407056100 + 46716067321 = 91690^2 + 216139^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 55123123421 - 2² = 55123123417 is a prime.

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 (55123123423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1258436 + ... + 1301501.

It is an arithmetic number, because the mean of its divisors is an integer number (7023189903).

Almost surely, 2^55123123421 is an apocalyptic number.

It is an amenable number.

55123123421 is a deficient number, since it is larger than the sum of its proper divisors (1062395803).

55123123421 is a wasteful number, since it uses less digits than its factorization.

55123123421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2560351.

The product of its digits is 7200, while the sum is 29.

Adding to 55123123421 its reverse (12432132155), we get a palindrome (67555255576).

The spelling of 55123123421 in words is "fifty-five billion, one hundred twenty-three million, one hundred twenty-three thousand, four hundred twenty-one".