51222551 has 4 divisors (see below), whose sum is σ = 51238992. Its totient is φ = 51206112.

The previous prime is 51222533. The next prime is 51222559. The reversal of 51222551 is 15522215.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51222551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51222559) 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, 1955 + ... + 10308.

It is an arithmetic number, because the mean of its divisors is an integer number (12809748).

Almost surely, 2^51222551 is an apocalyptic number.

51222551 is a deficient number, since it is larger than the sum of its proper divisors (16441).

51222551 is a wasteful number, since it uses less digits than its factorization.

51222551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16440.

The product of its digits is 1000, while the sum is 23.

The square root of 51222551 is about 7156.9931535527. The cubic root of 51222551 is about 371.3816155984.

Adding to 51222551 its reverse (15522215), we get a palindrome (66744766).

The spelling of 51222551 in words is "fifty-one million, two hundred twenty-two thousand, five hundred fifty-one".