5661557421 has 8 divisors (see below), whose sum is σ = 8129415840. Its totient is φ = 3484035312.

The previous prime is 5661557417. The next prime is 5661557441. The reversal of 5661557421 is 1247551665.

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

It is not a de Polignac number, because 5661557421 - 2² = 5661557417 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5661557411) 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, 72584031 + ... + 72584108.

It is an arithmetic number, because the mean of its divisors is an integer number (1016176980).

Almost surely, 2^5661557421 is an apocalyptic number.

It is an amenable number.

5661557421 is a deficient number, since it is larger than the sum of its proper divisors (2467858419).

5661557421 is a wasteful number, since it uses less digits than its factorization.

5661557421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145168155.

The product of its digits is 252000, while the sum is 42.

The square root of 5661557421 is about 75243.3214378525. The cubic root of 5661557421 is about 1782.2911015583.

The spelling of 5661557421 in words is "five billion, six hundred sixty-one million, five hundred fifty-seven thousand, four hundred twenty-one".