61918011819 has 24 divisors (see below), whose sum is σ = 92775533760. Its totient is φ = 41267139336.

The previous prime is 61918011811. The next prime is 61918011821. The reversal of 61918011819 is 91811081916.

It is a happy number.

61918011819 is a `hidden beast` number, since 619 + 1 + 8 + 0 + 1 + 18 + 19 = 666.

It is not a de Polignac number, because 61918011819 - 2³ = 61918011811 is a prime.

It is a super-2 number, since 2×61918011819² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (61918011811) 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, 884584 + ... + 952010.

It is an arithmetic number, because the mean of its divisors is an integer number (3865647240).

Almost surely, 2^61918011819 is an apocalyptic number.

61918011819 is a deficient number, since it is larger than the sum of its proper divisors (30857521941).

61918011819 is an equidigital number, since it uses as much as digits as its factorization.

61918011819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71221 (or 71209 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 45.

It can be divided in two parts, 6191 and 8011819, that added together give a triangular number (8018010 = T₄₀₀₄).

The spelling of 61918011819 in words is "sixty-one billion, nine hundred eighteen million, eleven thousand, eight hundred nineteen".