1618861861431 has 24 divisors (see below), whose sum is σ = 2339796928560. Its totient is φ = 1078576442496.

The previous prime is 1618861861427. The next prime is 1618861861483. The reversal of 1618861861431 is 1341681688161.

1618861861431 is a `hidden beast` number, since 1 + 6 + 1 + 8 + 8 + 6 + 18 + 614 + 3 + 1 = 666.

It is not a de Polignac number, because 1618861861431 - 2² = 1618861861427 is a prime.

It is a super-2 number, since 2×1618861861431² (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 (1618861861411) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 146378580 + ... + 146389638.

It is an arithmetic number, because the mean of its divisors is an integer number (97491538690).

Almost surely, 2^{1618861861431} is an apocalyptic number.

1618861861431 is a deficient number, since it is larger than the sum of its proper divisors (720935067129).

1618861861431 is a wasteful number, since it uses less digits than its factorization.

1618861861431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19615 (or 19612 counting only the distinct ones).

The product of its digits is 1327104, while the sum is 54.

The spelling of 1618861861431 in words is "one trillion, six hundred eighteen billion, eight hundred sixty-one million, eight hundred sixty-one thousand, four hundred thirty-one".