51521207 has 4 divisors (see below), whose sum is σ = 51551616. Its totient is φ = 51490800.

The previous prime is 51521201. The next prime is 51521209. The reversal of 51521207 is 70212515.

It is a happy number.

51521207 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 70212515 = 5 ⋅14042503.

It is a cyclic number.

It is not a de Polignac number, because 51521207 - 2¹² = 51517111 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 (51521201) 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, 12503 + ... + 16104.

It is an arithmetic number, because the mean of its divisors is an integer number (12887904).

Almost surely, 2^51521207 is an apocalyptic number.

51521207 is a deficient number, since it is larger than the sum of its proper divisors (30409).

51521207 is a wasteful number, since it uses less digits than its factorization.

51521207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30408.

The product of its (nonzero) digits is 700, while the sum is 23.

The square root of 51521207 is about 7177.8274568284. The cubic root of 51521207 is about 372.1020045358.

The spelling of 51521207 in words is "fifty-one million, five hundred twenty-one thousand, two hundred seven".