1642552581 has 16 divisors (see below), whose sum is σ = 2251434944. Its totient is φ = 1064409984.

The previous prime is 1642552573. The next prime is 1642552591. The reversal of 1642552581 is 1852552461.

It is not a de Polignac number, because 1642552581 - 2³ = 1642552573 is a prime.

It is a super-2 number, since 2×1642552581² = 5395957962699523122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1642552591) 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, 118065 + ... + 131241.

It is an arithmetic number, because the mean of its divisors is an integer number (140714684).

Almost surely, 2^1642552581 is an apocalyptic number.

It is an amenable number.

1642552581 is a deficient number, since it is larger than the sum of its proper divisors (608882363).

1642552581 is a wasteful number, since it uses less digits than its factorization.

1642552581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14340.

The product of its digits is 96000, while the sum is 39.

The square root of 1642552581 is about 40528.4169565010. The cubic root of 1642552581 is about 1179.8852184149.

It can be divided in two parts, 16425 and 52581, that added together give a triangular number (69006 = T₃₇₁).

The spelling of 1642552581 in words is "one billion, six hundred forty-two million, five hundred fifty-two thousand, five hundred eighty-one".