15540542421 has 8 divisors (see below), whose sum is σ = 20778442560. Its totient is φ = 10331501952.

The previous prime is 15540542399. The next prime is 15540542429. The reversal of 15540542421 is 12424504551.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 15540542421 - 2⁹ = 15540541909 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15540542429) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7213660 + ... + 7215813.

It is an arithmetic number, because the mean of its divisors is an integer number (2597305320).

Almost surely, 2^15540542421 is an apocalyptic number.

It is an amenable number.

15540542421 is a deficient number, since it is larger than the sum of its proper divisors (5237900139).

15540542421 is a wasteful number, since it uses less digits than its factorization.

15540542421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14429835.

The product of its (nonzero) digits is 32000, while the sum is 33.

The spelling of 15540542421 in words is "fifteen billion, five hundred forty million, five hundred forty-two thousand, four hundred twenty-one".