1644571145 has 16 divisors (see below), whose sum is σ = 2258427648. Its totient is φ = 1126198080.

The previous prime is 1644571141. The next prime is 1644571147. The reversal of 1644571145 is 5411754461.

It is not a de Polignac number, because 1644571145 - 2² = 1644571141 is a prime.

It is a super-2 number, since 2×1644571145² = 5409228501933222050, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1644571099 and 1644571108.

It is not an unprimeable number, because it can be changed into a prime (1644571141) 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, 4541 + ... + 57530.

It is an arithmetic number, because the mean of its divisors is an integer number (141151728).

Almost surely, 2^1644571145 is an apocalyptic number.

It is an amenable number.

1644571145 is a deficient number, since it is larger than the sum of its proper divisors (613856503).

1644571145 is an equidigital number, since it uses as much as digits as its factorization.

1644571145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62840.

The product of its digits is 67200, while the sum is 38.

The square root of 1644571145 is about 40553.3123801250. The cubic root of 1644571145 is about 1180.3683483293.

The spelling of 1644571145 in words is "one billion, six hundred forty-four million, five hundred seventy-one thousand, one hundred forty-five".