18461616157 has 4 divisors (see below), whose sum is σ = 19547593596. Its totient is φ = 17375638720.

The previous prime is 18461616139. The next prime is 18461616167. The reversal of 18461616157 is 75161616481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75161616481 = 7 ⋅10737373783.

It can be written as a sum of positive squares in 2 ways, for example, as 16337696761 + 2123919396 = 127819^2 + 46086^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18461616157 is a prime.

It is a super-2 number, since 2×18461616157² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18461616167) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 542988694 + ... + 542988727.

It is an arithmetic number, because the mean of its divisors is an integer number (4886898399).

Almost surely, 2^18461616157 is an apocalyptic number.

18461616157 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

18461616157 is a deficient number, since it is larger than the sum of its proper divisors (1085977439).

18461616157 is a wasteful number, since it uses less digits than its factorization.

18461616157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1085977438.

The product of its digits is 241920, while the sum is 46.

The spelling of 18461616157 in words is "eighteen billion, four hundred sixty-one million, six hundred sixteen thousand, one hundred fifty-seven".