15540520123 has 2 divisors, whose sum is σ = 15540520124. Its totient is φ = 15540520122.

The previous prime is 15540520081. The next prime is 15540520129. The reversal of 15540520123 is 32102504551.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15540520123 - 2²¹ = 15538422971 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 15540520091 and 15540520100.

It is not a weakly prime, because it can be changed into another prime (15540520129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7770260061 + 7770260062.

It is an arithmetic number, because the mean of its divisors is an integer number (7770260062).

Almost surely, 2^15540520123 is an apocalyptic number.

15540520123 is a deficient number, since it is larger than the sum of its proper divisors (1).

15540520123 is an equidigital number, since it uses as much as digits as its factorization.

15540520123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6000, while the sum is 28.

It can be divided in two parts, 155405 and 20123, that added together give a triangular number (175528 = T₅₉₂).

The spelling of 15540520123 in words is "fifteen billion, five hundred forty million, five hundred twenty thousand, one hundred twenty-three".