861439420694 has 4 divisors (see below), whose sum is σ = 1292159131044. Its totient is φ = 430719710346.

The previous prime is 861439420691. The next prime is 861439420697. The reversal of 861439420694 is 496024934168.

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

It is an interprime number because it is at equal distance from previous prime (861439420691) and next prime (861439420697).

It is a super-2 number, since 2×861439420694² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861439420691) 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 as a sum of consecutive naturals, namely, 215359855172 + ... + 215359855175.

It is an arithmetic number, because the mean of its divisors is an integer number (323039782761).

Almost surely, 2^861439420694 is an apocalyptic number.

861439420694 is a deficient number, since it is larger than the sum of its proper divisors (430719710350).

861439420694 is a wasteful number, since it uses less digits than its factorization.

861439420694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430719710349.

The product of its (nonzero) digits is 8957952, while the sum is 56.

The spelling of 861439420694 in words is "eight hundred sixty-one billion, four hundred thirty-nine million, four hundred twenty thousand, six hundred ninety-four".