55721716 has 12 divisors (see below), whose sum is σ = 103249188. Its totient is φ = 26221952.

The previous prime is 55721711. The next prime is 55721719. The reversal of 55721716 is 61712755.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 48720400 + 7001316 = 6980^2 + 2646^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55721711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 409651 + ... + 409786.

It is an arithmetic number, because the mean of its divisors is an integer number (8604099).

Almost surely, 2^55721716 is an apocalyptic number.

It is an amenable number.

55721716 is a deficient number, since it is larger than the sum of its proper divisors (47527472).

55721716 is a wasteful number, since it uses less digits than its factorization.

55721716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819458 (or 819456 counting only the distinct ones).

The product of its digits is 14700, while the sum is 34.

The square root of 55721716 is about 7464.6979845135. The cubic root of 55721716 is about 381.9514480110.

The spelling of 55721716 in words is "fifty-five million, seven hundred twenty-one thousand, seven hundred sixteen".