15506023745 has 4 divisors (see below), whose sum is σ = 18607228500. Its totient is φ = 12404818992.

The previous prime is 15506023721. The next prime is 15506023769. The reversal of 15506023745 is 54732060551.

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: 54732060551 = 7 ⋅7818865793.

It is an interprime number because it is at equal distance from previous prime (15506023721) and next prime (15506023769).

It can be written as a sum of positive squares in 2 ways, for example, as 6624657664 + 8881366081 = 81392^2 + 94241^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15506023745 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 15506023699 and 15506023708.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1550602370 + ... + 1550602379.

It is an arithmetic number, because the mean of its divisors is an integer number (4651807125).

Almost surely, 2^15506023745 is an apocalyptic number.

It is an amenable number.

15506023745 is a deficient number, since it is larger than the sum of its proper divisors (3101204755).

15506023745 is an equidigital number, since it uses as much as digits as its factorization.

15506023745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3101204754.

The product of its (nonzero) digits is 126000, while the sum is 38.

The spelling of 15506023745 in words is "fifteen billion, five hundred six million, twenty-three thousand, seven hundred forty-five".