644161354 has 4 divisors (see below), whose sum is σ = 966242034. Its totient is φ = 322080676.

The previous prime is 644161337. The next prime is 644161411. The reversal of 644161354 is 453161446.

644161354 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 453161446 = 2 ⋅226580723.

It can be written as a sum of positive squares in only one way, i.e., 641254329 + 2907025 = 25323^2 + 1705^2 .

It is a super-2 number, since 2×644161354² = 829887699974226632, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161040337 + ... + 161040340.

Almost surely, 2^644161354 is an apocalyptic number.

644161354 is a deficient number, since it is larger than the sum of its proper divisors (322080680).

644161354 is a wasteful number, since it uses less digits than its factorization.

644161354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322080679.

The product of its digits is 34560, while the sum is 34.

The square root of 644161354 is about 25380.3340009544. The cubic root of 644161354 is about 863.6376268508.

The spelling of 644161354 in words is "six hundred forty-four million, one hundred sixty-one thousand, three hundred fifty-four".