51581772 has 120 divisors (see below), whose sum is σ = 151118352. Its totient is φ = 15206400.

The previous prime is 51581767. The next prime is 51581809. The reversal of 51581772 is 27718515.

51581772 is a `hidden beast` number, since 5 + 1 + 581 + 7 + 72 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 145948 + ... + 146300.

Almost surely, 2^51581772 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 51581772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75559176).

51581772 is an abundant number, since it is smaller than the sum of its proper divisors (99536580).

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

51581772 is a wasteful number, since it uses less digits than its factorization.

51581772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421 (or 410 counting only the distinct ones).

The product of its digits is 19600, while the sum is 36.

The square root of 51581772 is about 7182.0451126403. The cubic root of 51581772 is about 372.2477537927.

The spelling of 51581772 in words is "fifty-one million, five hundred eighty-one thousand, seven hundred seventy-two".