51909623 has 4 divisors (see below), whose sum is σ = 53699640. Its totient is φ = 50119608.

The previous prime is 51909607. The next prime is 51909629. The reversal of 51909623 is 32690915.

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

It is a cyclic number.

It is not a de Polignac number, because 51909623 - 2⁴ = 51909607 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 (51909629) 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, 894965 + ... + 895022.

It is an arithmetic number, because the mean of its divisors is an integer number (13424910).

Almost surely, 2^51909623 is an apocalyptic number.

51909623 is a deficient number, since it is larger than the sum of its proper divisors (1790017).

51909623 is a wasteful number, since it uses less digits than its factorization.

51909623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1790016.

The product of its (nonzero) digits is 14580, while the sum is 35.

The square root of 51909623 is about 7204.8333082730. The cubic root of 51909623 is about 373.0347510790.

The spelling of 51909623 in words is "fifty-one million, nine hundred nine thousand, six hundred twenty-three".