7421528143521 has 80 divisors (see below), whose sum is σ = 11215973349504. Its totient is φ = 4890299774976.

The previous prime is 7421528143511. The next prime is 7421528143537. The reversal of 7421528143521 is 1253418251247.

It is a happy number.

7421528143521 is a `hidden beast` number, since 7 + 4 + 2 + 1 + 5 + 2 + 81 + 43 + 521 = 666.

It is not a de Polignac number, because 7421528143521 - 2⁵ = 7421528143489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7421528143511) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 3273721030 + ... + 3273723296.

Almost surely, 2^{7421528143521} is an apocalyptic number.

It is an amenable number.

7421528143521 is a deficient number, since it is larger than the sum of its proper divisors (3794445205983).

7421528143521 is a wasteful number, since it uses less digits than its factorization.

7421528143521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3732 (or 3723 counting only the distinct ones).

The product of its digits is 537600, while the sum is 45.

The spelling of 7421528143521 in words is "seven trillion, four hundred twenty-one billion, five hundred twenty-eight million, one hundred forty-three thousand, five hundred twenty-one".