551221543521 has 40 divisors (see below), whose sum is σ = 908380202400. Its totient is φ = 330319978560.

The previous prime is 551221543519. The next prime is 551221543571. The reversal of 551221543521 is 125345122155.

551221543521 is a `hidden beast` number, since 5 + 5 + 1 + 2 + 215 + 435 + 2 + 1 = 666.

It is not a de Polignac number, because 551221543521 - 2¹ = 551221543519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (551221543511) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3396291 + ... + 3554888.

It is an arithmetic number, because the mean of its divisors is an integer number (22709505060).

Almost surely, 2^551221543521 is an apocalyptic number.

It is an amenable number.

551221543521 is a deficient number, since it is larger than the sum of its proper divisors (357158658879).

551221543521 is a wasteful number, since it uses less digits than its factorization.

551221543521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6951291 (or 6951282 counting only the distinct ones).

The product of its digits is 60000, while the sum is 36.

Adding to 551221543521 its reverse (125345122155), we get a palindrome (676566665676).

The spelling of 551221543521 in words is "five hundred fifty-one billion, two hundred twenty-one million, five hundred forty-three thousand, five hundred twenty-one".