15550623581 has 2 divisors, whose sum is σ = 15550623582. Its totient is φ = 15550623580.

The previous prime is 15550623559. The next prime is 15550623619. The reversal of 15550623581 is 18532605551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13009455481 + 2541168100 = 114059^2 + 50410^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15550623581 is a prime.

It is a super-2 number, since 2×15550623581² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15550620581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7775311790 + 7775311791.

It is an arithmetic number, because the mean of its divisors is an integer number (7775311791).

Almost surely, 2^15550623581 is an apocalyptic number.

It is an amenable number.

15550623581 is a deficient number, since it is larger than the sum of its proper divisors (1).

15550623581 is an equidigital number, since it uses as much as digits as its factorization.

15550623581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 180000, while the sum is 41.

The spelling of 15550623581 in words is "fifteen billion, five hundred fifty million, six hundred twenty-three thousand, five hundred eighty-one".