51955440 has 40 divisors (see below), whose sum is σ = 161062608. Its totient is φ = 13854720.

The previous prime is 51955439. The next prime is 51955447. The reversal of 51955440 is 4455915.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51955447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 108001 + ... + 108480.

Almost surely, 2^51955440 is an apocalyptic number.

It is an amenable number.

51955440 is an abundant number, since it is smaller than the sum of its proper divisors (109107168).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51955440 is a wasteful number, since it uses less digits than its factorization.

51955440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216497 (or 216491 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 33.

The square root of 51955440 is about 7208.0122086467. The cubic root of 51955440 is about 373.1444693819.

The spelling of 51955440 in words is "fifty-one million, nine hundred fifty-five thousand, four hundred forty".