51538740 has 144 divisors (see below), whose sum is σ = 164451840. Its totient is φ = 12038400.

The previous prime is 51538727. The next prime is 51538741. The reversal of 51538740 is 4783515.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51538741) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 224946 + ... + 225174.

Almost surely, 2^51538740 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51538740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82225920).

51538740 is an abundant number, since it is smaller than the sum of its proper divisors (112913100).

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

51538740 is a wasteful number, since it uses less digits than its factorization.

51538740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294 (or 281 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 33.

The square root of 51538740 is about 7179.0486834956. The cubic root of 51538740 is about 372.1442093216.

The spelling of 51538740 in words is "fifty-one million, five hundred thirty-eight thousand, seven hundred forty".