51542121101 has 4 divisors (see below), whose sum is σ = 53783082912. Its totient is φ = 49301159292.

The previous prime is 51542121091. The next prime is 51542121133. The reversal of 51542121101 is 10112124515.

It is a happy number.

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 51542121101 - 2¹⁸ = 51541858957 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 2240961787 = 51542121101 / (5 + 1 + 5 + 4 + 2 + 1 + 2 + 1 + 1 + 0 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51542121151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1120480871 + ... + 1120480916.

It is an arithmetic number, because the mean of its divisors is an integer number (13445770728).

Almost surely, 2^51542121101 is an apocalyptic number.

It is an amenable number.

51542121101 is a deficient number, since it is larger than the sum of its proper divisors (2240961811).

51542121101 is a wasteful number, since it uses less digits than its factorization.

51542121101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2240961810.

The product of its (nonzero) digits is 400, while the sum is 23.

Adding to 51542121101 its reverse (10112124515), we get a palindrome (61654245616).

The spelling of 51542121101 in words is "fifty-one billion, five hundred forty-two million, one hundred twenty-one thousand, one hundred one".