55025721 has 24 divisors (see below), whose sum is σ = 81950856. Its totient is φ = 35562240.

The previous prime is 55025717. The next prime is 55025741. The reversal of 55025721 is 12752055.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 10989225 + 44036496 = 3315^2 + 6636^2 .

It is not a de Polignac number, because 55025721 - 2² = 55025717 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55025741) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39391 + ... + 40763.

It is an arithmetic number, because the mean of its divisors is an integer number (3414619).

Almost surely, 2^55025721 is an apocalyptic number.

It is an amenable number.

55025721 is a deficient number, since it is larger than the sum of its proper divisors (26925135).

55025721 is a wasteful number, since it uses less digits than its factorization.

55025721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1513 (or 1510 counting only the distinct ones).

The product of its (nonzero) digits is 3500, while the sum is 27.

The square root of 55025721 is about 7417.9323938683. The cubic root of 55025721 is about 380.3545191041.

Adding to 55025721 its reverse (12752055), we get a palindrome (67777776).

The spelling of 55025721 in words is "fifty-five million, twenty-five thousand, seven hundred twenty-one".