2421655561 has 4 divisors (see below), whose sum is σ = 2607936772. Its totient is φ = 2235374352.

The previous prime is 2421655547. The next prime is 2421655567. The reversal of 2421655561 is 1655561242.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 694006336 + 1727649225 = 26344^2 + 41565^2 .

It is a cyclic number.

It is not a de Polignac number, because 2421655561 - 2²¹ = 2419558409 is a prime.

It is a super-2 number, since 2×2421655561² = 11728831312244449442, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2421655561.

It is not an unprimeable number, because it can be changed into a prime (2421655567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93140586 + ... + 93140611.

It is an arithmetic number, because the mean of its divisors is an integer number (651984193).

Almost surely, 2^2421655561 is an apocalyptic number.

It is an amenable number.

2421655561 is a deficient number, since it is larger than the sum of its proper divisors (186281211).

2421655561 is a wasteful number, since it uses less digits than its factorization.

2421655561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186281210.

The product of its digits is 72000, while the sum is 37.

The square root of 2421655561 is about 49210.3196595999. The cubic root of 2421655561 is about 1342.8807781215.

The spelling of 2421655561 in words is "two billion, four hundred twenty-one million, six hundred fifty-five thousand, five hundred sixty-one".