61687657 has 6 divisors (see below), whose sum is σ = 63230654. Its totient is φ = 60181440.

The previous prime is 61687651. The next prime is 61687667. The reversal of 61687657 is 75678616.

It can be written as a sum of positive squares in 3 ways, for example, as 6170256 + 55517401 = 2484^2 + 7451^2 .

It is not a de Polignac number, because 61687657 - 2⁷ = 61687529 is a prime.

It is a super-2 number, since 2×61687657² = 7610734052299298, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61687651) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16668 + ... + 20029.

Almost surely, 2^61687657 is an apocalyptic number.

It is an amenable number.

61687657 is a deficient number, since it is larger than the sum of its proper divisors (1542997).

61687657 is an equidigital number, since it uses as much as digits as its factorization.

61687657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36779 (or 36738 counting only the distinct ones).

The product of its digits is 423360, while the sum is 46.

The square root of 61687657 is about 7854.1490309263. The cubic root of 61687657 is about 395.1234074695.

The spelling of 61687657 in words is "sixty-one million, six hundred eighty-seven thousand, six hundred fifty-seven".