1620108581 has 16 divisors (see below), whose sum is σ = 1997622144. Its totient is φ = 1279502784.

The previous prime is 1620108557. The next prime is 1620108593. The reversal of 1620108581 is 1858010261.

It is a de Polignac number, because none of the positive numbers 2^k-1620108581 is a prime.

It is a super-2 number, since 2×1620108581² = 5249503628459667122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620108521) 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, 34706 + ... + 66668.

It is an arithmetic number, because the mean of its divisors is an integer number (124851384).

Almost surely, 2^1620108581 is an apocalyptic number.

It is an amenable number.

1620108581 is a deficient number, since it is larger than the sum of its proper divisors (377513563).

1620108581 is a wasteful number, since it uses less digits than its factorization.

1620108581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32540.

The product of its (nonzero) digits is 3840, while the sum is 32.

The square root of 1620108581 is about 40250.5724307121. The cubic root of 1620108581 is about 1174.4865312856.

The spelling of 1620108581 in words is "one billion, six hundred twenty million, one hundred eight thousand, five hundred eighty-one".