521216370 has 80 divisors (see below), whose sum is σ = 1431416448. Its totient is φ = 136023840.

The previous prime is 521216369. The next prime is 521216401. The reversal of 521216370 is 73612125.

It is a happy number.

521216370 is a `hidden beast` number, since 5 + 2 + 1 + 21 + 637 + 0 = 666.

521216370 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 31225 + ... + 44915.

Almost surely, 2^521216370 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 521216370, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (715708224).

521216370 is an abundant number, since it is smaller than the sum of its proper divisors (910200078).

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

521216370 is a wasteful number, since it uses less digits than its factorization.

521216370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13757 (or 13748 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 521216370 is about 22830.1635999394. The cubic root of 521216370 is about 804.7716750189.

Adding to 521216370 its reverse (73612125), we get a palindrome (594828495).

The spelling of 521216370 in words is "five hundred twenty-one million, two hundred sixteen thousand, three hundred seventy".