15542312121 has 24 divisors (see below), whose sum is σ = 26092023360. Its totient is φ = 8730788256.

The previous prime is 15542312057. The next prime is 15542312207. The reversal of 15542312121 is 12121324551.

It is a happy number.

It is not a de Polignac number, because 15542312121 - 2⁶ = 15542312057 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15542312321) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2086990 + ... + 2094423.

It is an arithmetic number, because the mean of its divisors is an integer number (1087167640).

Almost surely, 2^15542312121 is an apocalyptic number.

It is an amenable number.

15542312121 is a deficient number, since it is larger than the sum of its proper divisors (10549711239).

15542312121 is a wasteful number, since it uses less digits than its factorization.

15542312121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4181485 (or 4181482 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

Adding to 15542312121 its reverse (12121324551), we get a palindrome (27663636672).

The spelling of 15542312121 in words is "fifteen billion, five hundred forty-two million, three hundred twelve thousand, one hundred twenty-one".