55723640 has 64 divisors (see below), whose sum is σ = 145359360. Its totient is φ = 18829440.

The previous prime is 55723639. The next prime is 55723643. The reversal of 55723640 is 4632755.

It is a super-3 number, since 3×55723640³ (a number of 24 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 55723597 and 55723606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55723643) 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, 18479 + ... + 21281.

It is an arithmetic number, because the mean of its divisors is an integer number (2271240).

Almost surely, 2^55723640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55723640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72679680).

55723640 is an abundant number, since it is smaller than the sum of its proper divisors (89635720).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55723640 is a wasteful number, since it uses less digits than its factorization.

55723640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2892 (or 2888 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 32.

The square root of 55723640 is about 7464.8268566659. The cubic root of 55723640 is about 381.9558440596.

The spelling of 55723640 in words is "fifty-five million, seven hundred twenty-three thousand, six hundred forty".