1645497280 has 336 divisors, whose sum is σ = 5041635840. Its totient is φ = 498769920.

The previous prime is 1645497277. The next prime is 1645497281. The reversal of 1645497280 is 827945461.

It is a super-2 number, since 2×1645497280² = 5415322596974796800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a self number, because there is not a number n which added to its sum of digits gives 1645497280.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645497281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 40134060 + ... + 40134100.

Almost surely, 2^1645497280 is an apocalyptic number.

1645497280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1645497280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2520817920).

1645497280 is an abundant number, since it is smaller than the sum of its proper divisors (3396138560).

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

1645497280 is a wasteful number, since it uses less digits than its factorization.

1645497280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148 (or 97 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 46.

The square root of 1645497280 is about 40564.7295072949. The cubic root of 1645497280 is about 1180.5898803075.

The spelling of 1645497280 in words is "one billion, six hundred forty-five million, four hundred ninety-seven thousand, two hundred eighty".