1861138632563 has 16 divisors (see below), whose sum is σ = 2219634034176. Its totient is φ = 1525806564480.

The previous prime is 1861138632541. The next prime is 1861138632611. The reversal of 1861138632563 is 3652368311681.

It is a cyclic number.

It is not a de Polignac number, because 1861138632563 - 2⁶ = 1861138632499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1861138632163) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2264768 + ... + 2975138.

It is an arithmetic number, because the mean of its divisors is an integer number (138727127136).

Almost surely, 2^{1861138632563} is an apocalyptic number.

1861138632563 is a deficient number, since it is larger than the sum of its proper divisors (358495401613).

1861138632563 is a wasteful number, since it uses less digits than its factorization.

1861138632563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 726674.

The product of its digits is 3732480, while the sum is 53.

The spelling of 1861138632563 in words is "one trillion, eight hundred sixty-one billion, one hundred thirty-eight million, six hundred thirty-two thousand, five hundred sixty-three".