1201566100 has 72 divisors (see below), whose sum is σ = 3015931968. Its totient is φ = 406982400.

The previous prime is 1201566097. The next prime is 1201566101. The reversal of 1201566100 is 16651021.

It is a super-2 number, since 2×1201566100² = 2887522185338420000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201566101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 47760 + ... + 68440.

It is an arithmetic number, because the mean of its divisors is an integer number (41887944).

Almost surely, 2^1201566100 is an apocalyptic number.

1201566100 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 1201566100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1507965984).

1201566100 is an abundant number, since it is smaller than the sum of its proper divisors (1814365868).

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

1201566100 is a wasteful number, since it uses less digits than its factorization.

1201566100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20785 (or 20778 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 1201566100 is about 34663.6134873443. The cubic root of 1201566100 is about 1063.1206542169.

The spelling of 1201566100 in words is "one billion, two hundred one million, five hundred sixty-six thousand, one hundred".