55420021565 has 48 divisors (see below), whose sum is σ = 71254753920. Its totient is φ = 41300772480.

The previous prime is 55420021543. The next prime is 55420021609. The reversal of 55420021565 is 56512002455.

It is a de Polignac number, because none of the positive numbers 2^k-55420021565 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 68335010 + ... + 68335820.

It is an arithmetic number, because the mean of its divisors is an integer number (1484474040).

Almost surely, 2^55420021565 is an apocalyptic number.

It is an amenable number.

55420021565 is a deficient number, since it is larger than the sum of its proper divisors (15834732355).

55420021565 is a wasteful number, since it uses less digits than its factorization.

55420021565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1202 (or 1155 counting only the distinct ones).

The product of its (nonzero) digits is 60000, while the sum is 35.

The spelling of 55420021565 in words is "fifty-five billion, four hundred twenty million, twenty-one thousand, five hundred sixty-five".