51209493 has 4 divisors (see below), whose sum is σ = 68279328. Its totient is φ = 34139660.

The previous prime is 51209467. The next prime is 51209537. The reversal of 51209493 is 39490215.

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 51209493 - 2¹³ = 51201301 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51209393) 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, 8534913 + ... + 8534918.

It is an arithmetic number, because the mean of its divisors is an integer number (17069832).

Almost surely, 2^51209493 is an apocalyptic number.

It is an amenable number.

51209493 is a deficient number, since it is larger than the sum of its proper divisors (17069835).

51209493 is a wasteful number, since it uses less digits than its factorization.

51209493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17069834.

The product of its (nonzero) digits is 9720, while the sum is 33.

The square root of 51209493 is about 7156.0808407955. The cubic root of 51209493 is about 371.3500545431.

The spelling of 51209493 in words is "fifty-one million, two hundred nine thousand, four hundred ninety-three".