51909949 has 32 divisors (see below), whose sum is σ = 66769920. Its totient is φ = 39267072.

The previous prime is 51909947. The next prime is 51909953. The reversal of 51909949 is 94990915.

It is not a de Polignac number, because 51909949 - 2¹ = 51909947 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51909899 and 51909908.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51909947) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 226567 + ... + 226795.

It is an arithmetic number, because the mean of its divisors is an integer number (2086560).

Almost surely, 2^51909949 is an apocalyptic number.

It is an amenable number.

51909949 is a deficient number, since it is larger than the sum of its proper divisors (14859971).

51909949 is a wasteful number, since it uses less digits than its factorization.

51909949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349.

The product of its (nonzero) digits is 131220, while the sum is 46.

The square root of 51909949 is about 7204.8559319392. The cubic root of 51909949 is about 373.0355319816.

The spelling of 51909949 in words is "fifty-one million, nine hundred nine thousand, nine hundred forty-nine".