2121617500 has 30 divisors (see below), whose sum is σ = 4639558616. Its totient is φ = 848646000.

The previous prime is 2121617489. The next prime is 2121617503. The reversal of 2121617500 is 57161212.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121617503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 421824 + ... + 426823.

Almost surely, 2^2121617500 is an apocalyptic number.

2121617500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2121617500 is an abundant number, since it is smaller than the sum of its proper divisors (2517941116).

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

2121617500 is an equidigital number, since it uses as much as digits as its factorization.

2121617500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 848671 (or 848654 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 25.

The square root of 2121617500 is about 46061.0193113439. The cubic root of 2121617500 is about 1284.9582871893.

Adding to 2121617500 its reverse (57161212), we get a palindrome (2178778712).

The spelling of 2121617500 in words is "two billion, one hundred twenty-one million, six hundred seventeen thousand, five hundred".