55621703721 has 8 divisors (see below), whose sum is σ = 75101034880. Its totient is φ = 36611754192.

The previous prime is 55621703633. The next prime is 55621703743. The reversal of 55621703721 is 12730712655.

It is a happy number.

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

It is not a de Polignac number, because 55621703721 - 2¹¹ = 55621701673 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 55621703721.

It is not an unprimeable number, because it can be changed into a prime (55621773721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117345130 + ... + 117345603.

It is an arithmetic number, because the mean of its divisors is an integer number (9387629360).

Almost surely, 2^55621703721 is an apocalyptic number.

It is an amenable number.

55621703721 is a deficient number, since it is larger than the sum of its proper divisors (19479331159).

55621703721 is a wasteful number, since it uses less digits than its factorization.

55621703721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234690815.

The product of its (nonzero) digits is 88200, while the sum is 39.

The spelling of 55621703721 in words is "fifty-five billion, six hundred twenty-one million, seven hundred three thousand, seven hundred twenty-one".