51161572 has 48 divisors (see below), whose sum is σ = 114250752. Its totient is φ = 19464480.

The previous prime is 51161557. The next prime is 51161573. The reversal of 51161572 is 27516115.

It is a super-2 number, since 2×51161572² = 5235012899022368, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a self number, because there is not a number n which added to its sum of digits gives 51161572.

It is not an unprimeable number, because it can be changed into a prime (51161573) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11313 + ... + 15175.

It is an arithmetic number, because the mean of its divisors is an integer number (2380224).

Almost surely, 2^51161572 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 51161572, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (57125376).

51161572 is an abundant number, since it is smaller than the sum of its proper divisors (63089180).

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

51161572 is a wasteful number, since it uses less digits than its factorization.

51161572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3928 (or 3926 counting only the distinct ones).

The product of its digits is 2100, while the sum is 28.

The square root of 51161572 is about 7152.7317858284. The cubic root of 51161572 is about 371.2341839710.

Adding to 51161572 its reverse (27516115), we get a palindrome (78677687).

The spelling of 51161572 in words is "fifty-one million, one hundred sixty-one thousand, five hundred seventy-two".