55078751721 has 16 divisors (see below), whose sum is σ = 84080225664. Its totient is φ = 31417060224.

The previous prime is 55078751719. The next prime is 55078751747. The reversal of 55078751721 is 12715787055.

It is not a de Polignac number, because 55078751721 - 2¹ = 55078751719 is a prime.

It is a super-2 number, since 2×55078751721² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55078751701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2342700 + ... + 2366093.

It is an arithmetic number, because the mean of its divisors is an integer number (5255014104).

Almost surely, 2^55078751721 is an apocalyptic number.

It is an amenable number.

55078751721 is a deficient number, since it is larger than the sum of its proper divisors (29001473943).

55078751721 is a wasteful number, since it uses less digits than its factorization.

55078751721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4709360.

The product of its (nonzero) digits is 686000, while the sum is 48.

The spelling of 55078751721 in words is "fifty-five billion, seventy-eight million, seven hundred fifty-one thousand, seven hundred twenty-one".