61684691 has 4 divisors (see below), whose sum is σ = 61700400. Its totient is φ = 61668984.

The previous prime is 61684681. The next prime is 61684709. The reversal of 61684691 is 19648616.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61684691 is a prime.

It is a super-2 number, since 2×61684691² = 7610002207530962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61684631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3890 + ... + 11768.

It is an arithmetic number, because the mean of its divisors is an integer number (15425100).

Almost surely, 2^61684691 is an apocalyptic number.

61684691 is a deficient number, since it is larger than the sum of its proper divisors (15709).

61684691 is an equidigital number, since it uses as much as digits as its factorization.

61684691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15708.

The product of its digits is 62208, while the sum is 41.

The square root of 61684691 is about 7853.9602112565. The cubic root of 61684691 is about 395.1170747342.

The spelling of 61684691 in words is "sixty-one million, six hundred eighty-four thousand, six hundred ninety-one".