51989730 has 64 divisors (see below), whose sum is σ = 135717120. Its totient is φ = 12669696.

The previous prime is 51989713. The next prime is 51989737. The reversal of 51989730 is 3798915.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (51989737) 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, 41899 + ... + 43121.

It is an arithmetic number, because the mean of its divisors is an integer number (2120580).

Almost surely, 2^51989730 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51989730, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67858560).

51989730 is an abundant number, since it is smaller than the sum of its proper divisors (83727390).

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

51989730 is a wasteful number, since it uses less digits than its factorization.

51989730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1355.

The product of its (nonzero) digits is 68040, while the sum is 42.

The square root of 51989730 is about 7210.3904193878. The cubic root of 51989730 is about 373.2265416988.

The spelling of 51989730 in words is "fifty-one million, nine hundred eighty-nine thousand, seven hundred thirty".