1613820681 has 72 divisors (see below), whose sum is σ = 2677114440. Its totient is φ = 934940160.

The previous prime is 1613820667. The next prime is 1613820731. The reversal of 1613820681 is 1860283161.

It can be written as a sum of positive squares in 4 ways, for example, as 331822656 + 1281998025 = 18216^2 + 35805^2 .

It is not a de Polignac number, because 1613820681 - 2¹⁰ = 1613819657 is a prime.

It is a super-2 number, since 2×1613820681² = 5208834380846607522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1613820641) 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, 4326411 + ... + 4326783.

It is an arithmetic number, because the mean of its divisors is an integer number (37182145).

Almost surely, 2^1613820681 is an apocalyptic number.

1613820681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1613820681 is a deficient number, since it is larger than the sum of its proper divisors (1063293759).

1613820681 is a wasteful number, since it uses less digits than its factorization.

1613820681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 567 (or 553 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 1613820681 is about 40172.3870463282. The cubic root of 1613820681 is about 1172.9651047196.

The spelling of 1613820681 in words is "one billion, six hundred thirteen million, eight hundred twenty thousand, six hundred eighty-one".