861719949450 has 144 divisors (see below), whose sum is σ = 2447122392000. Its totient is φ = 216793843200.

The previous prime is 861719949449. The next prime is 861719949451. The reversal of 861719949450 is 54949917168.

861719949450 is a `hidden beast` number, since 8 + 6 + 1 + 7 + 1 + 99 + 494 + 50 = 666.

It is an interprime number because it is at equal distance from previous prime (861719949449) and next prime (861719949451).

It is a super-2 number, since 2×861719949450² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (861719949451) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1851451 + ... + 2269649.

It is an arithmetic number, because the mean of its divisors is an integer number (16993905500).

Almost surely, 2^861719949450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 861719949450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1223561196000).

861719949450 is an abundant number, since it is smaller than the sum of its proper divisors (1585402442550).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

861719949450 is a wasteful number, since it uses less digits than its factorization.

861719949450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418477 (or 418469 counting only the distinct ones).

The product of its (nonzero) digits is 19595520, while the sum is 63.

The spelling of 861719949450 in words is "eight hundred sixty-one billion, seven hundred nineteen million, nine hundred forty-nine thousand, four hundred fifty".