2101121550 has 144 divisors (see below), whose sum is σ = 6217316352. Its totient is φ = 504475200.

The previous prime is 2101121497. The next prime is 2101121557. The reversal of 2101121550 is 551211012.

2101121550 is a `hidden beast` number, since 2 + 1 + 0 + 112 + 1 + 550 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101121557) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 527667 + ... + 531633.

It is an arithmetic number, because the mean of its divisors is an integer number (43175808).

Almost surely, 2^2101121550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2101121550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3108658176).

2101121550 is an abundant number, since it is smaller than the sum of its proper divisors (4116194802).

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

2101121550 is a wasteful number, since it uses less digits than its factorization.

2101121550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4103 (or 4095 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 18.

The square root of 2101121550 is about 45837.9924298611. The cubic root of 2101121550 is about 1280.8070979962.

Adding to 2101121550 its reverse (551211012), we get a palindrome (2652332562).

The spelling of 2101121550 in words is "two billion, one hundred one million, one hundred twenty-one thousand, five hundred fifty".