1644161051 has 4 divisors (see below), whose sum is σ = 1770634992. Its totient is φ = 1517687112.

The previous prime is 1644161009. The next prime is 1644161053. The reversal of 1644161051 is 1501614461.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1644161051 - 2²² = 1639966747 is a prime.

It is a super-3 number, since 3×1644161051³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1644161053) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63236951 + ... + 63236976.

It is an arithmetic number, because the mean of its divisors is an integer number (442658748).

Almost surely, 2^1644161051 is an apocalyptic number.

1644161051 is a deficient number, since it is larger than the sum of its proper divisors (126473941).

1644161051 is a wasteful number, since it uses less digits than its factorization.

1644161051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126473940.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 1644161051 is about 40548.2558317864. The cubic root of 1644161051 is about 1180.2702270612.

The spelling of 1644161051 in words is "one billion, six hundred forty-four million, one hundred sixty-one thousand, fifty-one".