1581619164 has 12 divisors (see below), whose sum is σ = 3690444744. Its totient is φ = 527206384.

The previous prime is 1581619159. The next prime is 1581619189. The reversal of 1581619164 is 4619161851.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65900787 + ... + 65900810.

It is an arithmetic number, because the mean of its divisors is an integer number (307537062).

Almost surely, 2^1581619164 is an apocalyptic number.

It is an amenable number.

1581619164 is an abundant number, since it is smaller than the sum of its proper divisors (2108825580).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1581619164 is a wasteful number, since it uses less digits than its factorization.

1581619164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131801604 (or 131801602 counting only the distinct ones).

The product of its digits is 51840, while the sum is 42.

The square root of 1581619164 is about 39769.5758589402. The cubic root of 1581619164 is about 1165.1110098250. Note that the first 3 decimals are identical.

It can be divided in two parts, 15816 and 19164, that added together give a triangular number (34980 = T₂₆₄).

The spelling of 1581619164 in words is "one billion, five hundred eighty-one million, six hundred nineteen thousand, one hundred sixty-four".