5251221020 has 24 divisors (see below), whose sum is σ = 11034730224. Its totient is φ = 2099123456.

The previous prime is 5251221013. The next prime is 5251221047. The reversal of 5251221020 is 201221525.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 5251220983 and 5251221001.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53474 + ... + 115593.

It is an arithmetic number, because the mean of its divisors is an integer number (459780426).

Almost surely, 2^5251221020 is an apocalyptic number.

It is an amenable number.

5251221020 is an abundant number, since it is smaller than the sum of its proper divisors (5783509204).

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

5251221020 is a wasteful number, since it uses less digits than its factorization.

5251221020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170629 (or 170627 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 5251221020 is about 72465.3090795865. The cubic root of 5251221020 is about 1738.1480516196.

Adding to 5251221020 its reverse (201221525), we get a palindrome (5452442545).

The spelling of 5251221020 in words is "five billion, two hundred fifty-one million, two hundred twenty-one thousand, twenty".