15501420861 has 4 divisors (see below), whose sum is σ = 20668561152. Its totient is φ = 10334280572.

The previous prime is 15501420859. The next prime is 15501420889. The reversal of 15501420861 is 16802410551.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 15501420861 - 2¹ = 15501420859 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15501420661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2583570141 + ... + 2583570146.

It is an arithmetic number, because the mean of its divisors is an integer number (5167140288).

Almost surely, 2^15501420861 is an apocalyptic number.

It is an amenable number.

15501420861 is a deficient number, since it is larger than the sum of its proper divisors (5167140291).

15501420861 is an equidigital number, since it uses as much as digits as its factorization.

15501420861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5167140290.

The product of its (nonzero) digits is 9600, while the sum is 33.

The spelling of 15501420861 in words is "fifteen billion, five hundred one million, four hundred twenty thousand, eight hundred sixty-one".