51285861 has 24 divisors (see below), whose sum is σ = 81038880. Its totient is φ = 30996000.

The previous prime is 51285859. The next prime is 51285893. The reversal of 51285861 is 16858215.

51285861 is a `hidden beast` number, since 51 + 28 + 586 + 1 = 666.

It is not a de Polignac number, because 51285861 - 2¹ = 51285859 is a prime.

It is a super-2 number, since 2×51285861² = 5260479077022642, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51285061) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 69030 + ... + 69768.

It is an arithmetic number, because the mean of its divisors is an integer number (3376620).

Almost surely, 2^51285861 is an apocalyptic number.

It is an amenable number.

51285861 is a deficient number, since it is larger than the sum of its proper divisors (29753019).

51285861 is a wasteful number, since it uses less digits than its factorization.

51285861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1457 (or 1454 counting only the distinct ones).

The product of its digits is 19200, while the sum is 36.

The square root of 51285861 is about 7161.4147345340. The cubic root of 51285861 is about 371.5345592363.

The spelling of 51285861 in words is "fifty-one million, two hundred eighty-five thousand, eight hundred sixty-one".