61918619 has 4 divisors (see below), whose sum is σ = 70764144. Its totient is φ = 53073096.

The previous prime is 61918613. The next prime is 61918621. The reversal of 61918619 is 91681916.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61918619 - 2¹⁶ = 61853083 is a prime.

It is a super-2 number, since 2×61918619² = 7667830757734322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61918613) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4422752 + ... + 4422765.

It is an arithmetic number, because the mean of its divisors is an integer number (17691036).

Almost surely, 2^61918619 is an apocalyptic number.

61918619 is a deficient number, since it is larger than the sum of its proper divisors (8845525).

61918619 is an equidigital number, since it uses as much as digits as its factorization.

61918619 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8845524.

The product of its digits is 23328, while the sum is 41.

The square root of 61918619 is about 7868.8384784541. The cubic root of 61918619 is about 395.6159146197.

The spelling of 61918619 in words is "sixty-one million, nine hundred eighteen thousand, six hundred nineteen".