15616611551 has 4 divisors (see below), whose sum is σ = 15621621600. Its totient is φ = 15611601504.

The previous prime is 15616611503. The next prime is 15616611581. The reversal of 15616611551 is 15511661651.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15511661651 = 41 ⋅378333211.

It is a cyclic number.

It is not a de Polignac number, because 15616611551 - 2³⁰ = 14542869727 is a prime.

It is a super-4 number, since 4×15616611551⁴ (a number of 42 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15616611581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2500346 + ... + 2506583.

It is an arithmetic number, because the mean of its divisors is an integer number (3905405400).

Almost surely, 2^15616611551 is an apocalyptic number.

15616611551 is a deficient number, since it is larger than the sum of its proper divisors (5010049).

15616611551 is an equidigital number, since it uses as much as digits as its factorization.

15616611551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5010048.

The product of its digits is 27000, while the sum is 38.

The spelling of 15616611551 in words is "fifteen billion, six hundred sixteen million, six hundred eleven thousand, five hundred fifty-one".