55123621 has 16 divisors (see below), whose sum is σ = 64880640. Its totient is φ = 45854640.

The previous prime is 55123613. The next prime is 55123631. The reversal of 55123621 is 12632155.

55123621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 55123621 - 2³ = 55123613 is a prime.

It is a super-2 number, since 2×55123621² = 6077227184303282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55123631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42460 + ... + 43738.

It is an arithmetic number, because the mean of its divisors is an integer number (4055040).

Almost surely, 2^55123621 is an apocalyptic number.

It is an amenable number.

55123621 is a deficient number, since it is larger than the sum of its proper divisors (9757019).

55123621 is a wasteful number, since it uses less digits than its factorization.

55123621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1464.

The product of its digits is 1800, while the sum is 25.

The square root of 55123621 is about 7424.5283351874. The cubic root of 55123621 is about 380.5799569848.

Adding to 55123621 its reverse (12632155), we get a palindrome (67755776).

The spelling of 55123621 in words is "fifty-five million, one hundred twenty-three thousand, six hundred twenty-one".