1021616125 has 32 divisors (see below), whose sum is σ = 1301620320. Its totient is φ = 800409600.

The previous prime is 1021616117. The next prime is 1021616143. The reversal of 1021616125 is 5216161201.

It is a happy number.

It can be written as a sum of positive squares in 16 ways, for example, as 878885316 + 142730809 = 29646^2 + 11947^2 .

It is not a de Polignac number, because 1021616125 - 2³ = 1021616117 is a prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 1021616125.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1321239 + ... + 1322011.

It is an arithmetic number, because the mean of its divisors is an integer number (40675635).

Almost surely, 2^1021616125 is an apocalyptic number.

It is an amenable number.

1021616125 is a deficient number, since it is larger than the sum of its proper divisors (280004195).

1021616125 is an equidigital number, since it uses as much as digits as its factorization.

1021616125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 994 (or 984 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 1021616125 is about 31962.7302494640. The cubic root of 1021616125 is about 1007.1540722007.

Adding to 1021616125 its reverse (5216161201), we get a palindrome (6237777326).

The spelling of 1021616125 in words is "one billion, twenty-one million, six hundred sixteen thousand, one hundred twenty-five".