61991434 has 4 divisors (see below), whose sum is σ = 92987154. Its totient is φ = 30995716.

The previous prime is 61991431. The next prime is 61991441. The reversal of 61991434 is 43419916.

61991434 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in only one way, i.e., 61575409 + 416025 = 7847^2 + 645^2 .

It is a junction number, because it is equal to n+sod(n) for n = 61991393 and 61991402.

It is not an unprimeable number, because it can be changed into a prime (61991431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15497857 + ... + 15497860.

Almost surely, 2^61991434 is an apocalyptic number.

61991434 is a deficient number, since it is larger than the sum of its proper divisors (30995720).

61991434 is a wasteful number, since it uses less digits than its factorization.

61991434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30995719.

The product of its digits is 23328, while the sum is 37.

The square root of 61991434 is about 7873.4639136787. The cubic root of 61991434 is about 395.7709325481.

The spelling of 61991434 in words is "sixty-one million, nine hundred ninety-one thousand, four hundred thirty-four".