1861864958078 has 16 divisors (see below), whose sum is σ = 2888759185920. Its totient is φ = 899067552600.

The previous prime is 1861864958071. The next prime is 1861864958111. The reversal of 1861864958078 is 8708594681681.

It is a super-2 number, since 2×1861864958078² (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 (1861864958071) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30550088 + ... + 30610971.

It is an arithmetic number, because the mean of its divisors is an integer number (180547449120).

Almost surely, 2^{1861864958078} is an apocalyptic number.

1861864958078 is a deficient number, since it is larger than the sum of its proper divisors (1026894227842).

1861864958078 is a wasteful number, since it uses less digits than its factorization.

1861864958078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61161583.

The product of its (nonzero) digits is 185794560, while the sum is 71.

The spelling of 1861864958078 in words is "one trillion, eight hundred sixty-one billion, eight hundred sixty-four million, nine hundred fifty-eight thousand, seventy-eight".