51661485 has 24 divisors (see below), whose sum is σ = 91240344. Its totient is φ = 27031680.

The previous prime is 51661481. The next prime is 51661501. The reversal of 51661485 is 58416615.

51661485 is a `hidden beast` number, since 516 + 61 + 4 + 85 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 5774409 + 45887076 = 2403^2 + 6774^2 .

It is not a de Polignac number, because 51661485 - 2² = 51661481 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51661481) 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, 8446 + ... + 13215.

It is an arithmetic number, because the mean of its divisors is an integer number (3801681).

Almost surely, 2^51661485 is an apocalyptic number.

It is an amenable number.

51661485 is a deficient number, since it is larger than the sum of its proper divisors (39578859).

51661485 is a wasteful number, since it uses less digits than its factorization.

51661485 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21725 (or 21722 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The square root of 51661485 is about 7187.5924341882. The cubic root of 51661485 is about 372.4394087895.

It can be divided in two parts, 516 and 61485, that added together give a square (62001 = 249²).

The spelling of 51661485 in words is "fifty-one million, six hundred sixty-one thousand, four hundred eighty-five".