15551223901 has 2 divisors, whose sum is σ = 15551223902. Its totient is φ = 15551223900.

The previous prime is 15551223893. The next prime is 15551224043. The reversal of 15551223901 is 10932215551.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13931080900 + 1620143001 = 118030^2 + 40251^2 .

It is a cyclic number.

It is not a de Polignac number, because 15551223901 - 2³ = 15551223893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15551223301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7775611950 + 7775611951.

It is an arithmetic number, because the mean of its divisors is an integer number (7775611951).

Almost surely, 2^15551223901 is an apocalyptic number.

It is an amenable number.

15551223901 is a deficient number, since it is larger than the sum of its proper divisors (1).

15551223901 is an equidigital number, since it uses as much as digits as its factorization.

15551223901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13500, while the sum is 34.

The spelling of 15551223901 in words is "fifteen billion, five hundred fifty-one million, two hundred twenty-three thousand, nine hundred one".