1644231540 has 48 divisors (see below), whose sum is σ = 5261542272. Its totient is φ = 375824256.

The previous prime is 1644231469. The next prime is 1644231559. The reversal of 1644231540 is 451324461.

It is a super-3 number, since 3×1644231540³ (a number of 29 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1644231498 and 1644231507.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1956999 + ... + 1957838.

It is an arithmetic number, because the mean of its divisors is an integer number (109615464).

Almost surely, 2^1644231540 is an apocalyptic number.

1644231540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1644231540 is an abundant number, since it is smaller than the sum of its proper divisors (3617310732).

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

1644231540 is a wasteful number, since it uses less digits than its factorization.

1644231540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3914856 (or 3914854 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 1644231540 is about 40549.1250213861. The cubic root of 1644231540 is about 1180.2870937948.

The spelling of 1644231540 in words is "one billion, six hundred forty-four million, two hundred thirty-one thousand, five hundred forty".