4021561600 has 108 divisors (see below), whose sum is σ = 11376119104. Its totient is φ = 1378805760.

The previous prime is 4021561559. The next prime is 4021561601. The reversal of 4021561600 is 61651204.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (4021561601) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 84 + ... + 89683.

Almost surely, 2^4021561600 is an apocalyptic number.

4021561600 is a gapful number since it is divisible by the number (40) 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 4021561600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5688059552).

4021561600 is an abundant number, since it is smaller than the sum of its proper divisors (7354557504).

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

4021561600 is an equidigital number, since it uses as much as digits as its factorization.

4021561600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89800 (or 89781 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 4021561600 is about 63415.7835242931. The cubic root of 4021561600 is about 1590.2481845620.

The spelling of 4021561600 in words is "four billion, twenty-one million, five hundred sixty-one thousand, six hundred".