55021740 has 48 divisors (see below), whose sum is σ = 156371712. Its totient is φ = 14452416.

The previous prime is 55021723. The next prime is 55021751. The reversal of 55021740 is 4712055.

It is a self number, because there is not a number n which added to its sum of digits gives 55021740.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2824 + ... + 10863.

It is an arithmetic number, because the mean of its divisors is an integer number (3257744).

Almost surely, 2^55021740 is an apocalyptic number.

It is an amenable number.

55021740 is an abundant number, since it is smaller than the sum of its proper divisors (101349972).

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

55021740 is a wasteful number, since it uses less digits than its factorization.

55021740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13766 (or 13764 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 24.

The square root of 55021740 is about 7417.6640527864. The cubic root of 55021740 is about 380.3453462553.

Adding to 55021740 its reverse (4712055), we get a palindrome (59733795).

The spelling of 55021740 in words is "fifty-five million, twenty-one thousand, seven hundred forty".