55621740 has 96 divisors (see below), whose sum is σ = 165957120. Its totient is φ = 13879296.

The previous prime is 55621733. The next prime is 55621757. The reversal of 55621740 is 4712655.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 55621698 and 55621707.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 110329 + ... + 110831.

It is an arithmetic number, because the mean of its divisors is an integer number (1728720).

Almost surely, 2^55621740 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 55621740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82978560).

55621740 is an abundant number, since it is smaller than the sum of its proper divisors (110335380).

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

55621740 is a wasteful number, since it uses less digits than its factorization.

55621740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 631 (or 629 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 55621740 is about 7457.9983909894. The cubic root of 55621740 is about 381.7228786052.

The spelling of 55621740 in words is "fifty-five million, six hundred twenty-one thousand, seven hundred forty".