6221553660 has 144 divisors (see below), whose sum is σ = 21653102016. Its totient is φ = 1416462336.

The previous prime is 6221553643. The next prime is 6221553673. The reversal of 6221553660 is 663551226.

It is a happy number.

6221553660 is a `hidden beast` number, since 62 + 2 + 1 + 5 + 536 + 60 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 314214 + ... + 333426.

It is an arithmetic number, because the mean of its divisors is an integer number (150368764).

Almost surely, 2^6221553660 is an apocalyptic number.

6221553660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6221553660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10826551008).

6221553660 is an abundant number, since it is smaller than the sum of its proper divisors (15431548356).

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

6221553660 is a wasteful number, since it uses less digits than its factorization.

6221553660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19492 (or 19487 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The square root of 6221553660 is about 78876.8258742706. The cubic root of 6221553660 is about 1839.2169064489.

The spelling of 6221553660 in words is "six billion, two hundred twenty-one million, five hundred fifty-three thousand, six hundred sixty".