521661140 has 192 divisors, whose sum is σ = 1495646208. Its totient is φ = 147571200.

The previous prime is 521661121. The next prime is 521661157. The reversal of 521661140 is 41166125.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1421237 + ... + 1421603.

It is an arithmetic number, because the mean of its divisors is an integer number (7789824).

Almost surely, 2^521661140 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 521661140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (747823104).

521661140 is an abundant number, since it is smaller than the sum of its proper divisors (973985068).

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

521661140 is a wasteful number, since it uses less digits than its factorization.

521661140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478 (or 476 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 521661140 is about 22839.9023640645. The cubic root of 521661140 is about 805.0005220989. Note that the first 3 decimals are identical.

The spelling of 521661140 in words is "five hundred twenty-one million, six hundred sixty-one thousand, one hundred forty".