1644222144 has 56 divisors (see below), whose sum is σ = 4490687488. Its totient is φ = 530392320.

The previous prime is 1644222131. The next prime is 1644222157. The reversal of 1644222144 is 4412224461.

It is an interprime number because it is at equal distance from previous prime (1644222131) and next prime (1644222157).

It is a super-3 number, since 3×1644222144³ (a number of 29 digits) contains 333 as substring.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132172 + ... + 144075.

It is an arithmetic number, because the mean of its divisors is an integer number (80190848).

Almost surely, 2^1644222144 is an apocalyptic number.

It is an amenable number.

1644222144 is an abundant number, since it is smaller than the sum of its proper divisors (2846465344).

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

1644222144 is a wasteful number, since it uses less digits than its factorization.

1644222144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276293 (or 276283 counting only the distinct ones).

The product of its digits is 12288, while the sum is 30.

The square root of 1644222144 is about 40549.0091617539. The cubic root of 1644222144 is about 1180.2848455310.

The spelling of 1644222144 in words is "one billion, six hundred forty-four million, two hundred twenty-two thousand, one hundred forty-four".