15551621207 has 2 divisors, whose sum is σ = 15551621208. Its totient is φ = 15551621206.

The previous prime is 15551621203. The next prime is 15551621237. The reversal of 15551621207 is 70212615551.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 15551621207 - 2² = 15551621203 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15551621203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7775810603 + 7775810604.

It is an arithmetic number, because the mean of its divisors is an integer number (7775810604).

Almost surely, 2^15551621207 is an apocalyptic number.

15551621207 is a deficient number, since it is larger than the sum of its proper divisors (1).

15551621207 is an equidigital number, since it uses as much as digits as its factorization.

15551621207 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21000, while the sum is 35.

The spelling of 15551621207 in words is "fifteen billion, five hundred fifty-one million, six hundred twenty-one thousand, two hundred seven".