1553640220 has 96 divisors (see below), whose sum is σ = 3649282560. Its totient is φ = 550851840.

The previous prime is 1553640211. The next prime is 1553640223. The reversal of 1553640220 is 220463551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1553640223) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1606177 + ... + 1607143.

It is an arithmetic number, because the mean of its divisors is an integer number (38013360).

Almost surely, 2^1553640220 is an apocalyptic number.

1553640220 is a gapful number since it is divisible by the number (10) 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 1553640220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1824641280).

1553640220 is an abundant number, since it is smaller than the sum of its proper divisors (2095642340).

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

1553640220 is a wasteful number, since it uses less digits than its factorization.

1553640220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1163 (or 1161 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 1553640220 is about 39416.2430984994. The cubic root of 1553640220 is about 1158.1997988789.

The spelling of 1553640220 in words is "one billion, five hundred fifty-three million, six hundred forty thousand, two hundred twenty".