521023140 has 288 divisors, whose sum is σ = 1907732736. Its totient is φ = 113541120.

The previous prime is 521023109. The next prime is 521023201. The reversal of 521023140 is 41320125.

521023140 is a `hidden beast` number, since 521 + 0 + 2 + 3 + 140 = 666.

It is a super-2 number, since 2×521023140² = 542930224830919200, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 773844 + ... + 774516.

It is an arithmetic number, because the mean of its divisors is an integer number (6624072).

Almost surely, 2^521023140 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 521023140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (953866368).

521023140 is an abundant number, since it is smaller than the sum of its proper divisors (1386709596).

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

521023140 is a wasteful number, since it uses less digits than its factorization.

521023140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 739 (or 734 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 521023140 is about 22825.9313063016. The cubic root of 521023140 is about 804.6722120060.

Adding to 521023140 its reverse (41320125), we get a palindrome (562343265).

The spelling of 521023140 in words is "five hundred twenty-one million, twenty-three thousand, one hundred forty".