51561144 has 32 divisors (see below), whose sum is σ = 143226000. Its totient is φ = 17186976.

The previous prime is 51561137. The next prime is 51561151. The reversal of 51561144 is 44116515.

51561144 is a `hidden beast` number, since 5 + 1 + 5 + 611 + 44 = 666.

It is an interprime number because it is at equal distance from previous prime (51561137) and next prime (51561151).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 119139 + ... + 119570.

Almost surely, 2^51561144 is an apocalyptic number.

51561144 is a gapful number since it is divisible by the number (54) formed by its first and last digit.

It is an amenable number.

51561144 is an abundant number, since it is smaller than the sum of its proper divisors (91664856).

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

51561144 is a wasteful number, since it uses less digits than its factorization.

51561144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238724 (or 238714 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 51561144 is about 7180.6088878312. The cubic root of 51561144 is about 372.1981254699.

Adding to 51561144 its reverse (44116515), we get a palindrome (95677659).

The spelling of 51561144 in words is "fifty-one million, five hundred sixty-one thousand, one hundred forty-four".