51981552 has 180 divisors, whose sum is σ = 173660760. Its totient is φ = 14466816.

The previous prime is 51981533. The next prime is 51981557. The reversal of 51981552 is 25518915.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51981557) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 373899 + ... + 374037.

It is an arithmetic number, because the mean of its divisors is an integer number (964782).

Almost surely, 2^51981552 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 51981552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86830380).

51981552 is an abundant number, since it is smaller than the sum of its proper divisors (121679208).

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

51981552 is a wasteful number, since it uses less digits than its factorization.

51981552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220 (or 204 counting only the distinct ones).

The product of its digits is 18000, while the sum is 36.

The square root of 51981552 is about 7209.8232988056. The cubic root of 51981552 is about 373.2069711239.

The spelling of 51981552 in words is "fifty-one million, nine hundred eighty-one thousand, five hundred fifty-two".