1601640405 has 16 divisors (see below), whose sum is σ = 2847360960. Its totient is φ = 854208144.

The previous prime is 1601640361. The next prime is 1601640409. The reversal of 1601640405 is 5040461061.

1601640405 is a `hidden beast` number, since 16 + 0 + 1 + 640 + 4 + 0 + 5 = 666.

It is not a de Polignac number, because 1601640405 - 2¹⁶ = 1601574869 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1601640409) 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, 5931867 + ... + 5932136.

It is an arithmetic number, because the mean of its divisors is an integer number (177960060).

Almost surely, 2^1601640405 is an apocalyptic number.

1601640405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1601640405 is a deficient number, since it is larger than the sum of its proper divisors (1245720555).

1601640405 is a wasteful number, since it uses less digits than its factorization.

1601640405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11864017 (or 11864011 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 1601640405 is about 40020.4998094726. The cubic root of 1601640405 is about 1170.0066732032.

The spelling of 1601640405 in words is "one billion, six hundred one million, six hundred forty thousand, four hundred five".