521405512394 has 16 divisors (see below), whose sum is σ = 856546215840. Its totient is φ = 236569905840.

The previous prime is 521405512393. The next prime is 521405512427. The reversal of 521405512394 is 493215504125.

It is a super-2 number, since 2×521405512394² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (521405512393) 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, 169948112 + ... + 169951179.

It is an arithmetic number, because the mean of its divisors is an integer number (53534138490).

Almost surely, 2^521405512394 is an apocalyptic number.

521405512394 is a deficient number, since it is larger than the sum of its proper divisors (335140703446).

521405512394 is a wasteful number, since it uses less digits than its factorization.

521405512394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339899365.

The product of its (nonzero) digits is 216000, while the sum is 41.

The spelling of 521405512394 in words is "five hundred twenty-one billion, four hundred five million, five hundred twelve thousand, three hundred ninety-four".