521987407 has 8 divisors (see below), whose sum is σ = 532337184. Its totient is φ = 511656288.

The previous prime is 521987383. The next prime is 521987413. The reversal of 521987407 is 704789125.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-521987407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521987467) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60793 + ... + 68845.

It is an arithmetic number, because the mean of its divisors is an integer number (66542148).

Almost surely, 2^521987407 is an apocalyptic number.

521987407 is a deficient number, since it is larger than the sum of its proper divisors (10349777).

521987407 is a wasteful number, since it uses less digits than its factorization.

521987407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9329.

The product of its (nonzero) digits is 141120, while the sum is 43.

The square root of 521987407 is about 22847.0437256114. The cubic root of 521987407 is about 805.1683132492.

The spelling of 521987407 in words is "five hundred twenty-one million, nine hundred eighty-seven thousand, four hundred seven".