15551661737 has 2 divisors, whose sum is σ = 15551661738. Its totient is φ = 15551661736.

The previous prime is 15551661707. The next prime is 15551661757. The reversal of 15551661737 is 73716615551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12316782361 + 3234879376 = 110981^2 + 56876^2 .

It is a cyclic number.

It is not a de Polignac number, because 15551661737 - 2¹⁸ = 15551399593 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 15551661691 and 15551661700.

It is not a weakly prime, because it can be changed into another prime (15551661707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7775830868 + 7775830869.

It is an arithmetic number, because the mean of its divisors is an integer number (7775830869).

Almost surely, 2^15551661737 is an apocalyptic number.

It is an amenable number.

15551661737 is a deficient number, since it is larger than the sum of its proper divisors (1).

15551661737 is an equidigital number, since it uses as much as digits as its factorization.

15551661737 is an evil number, because the sum of its binary digits is even.

The product of its digits is 661500, while the sum is 47.

The spelling of 15551661737 in words is "fifteen billion, five hundred fifty-one million, six hundred sixty-one thousand, seven hundred thirty-seven".