1663960840 has 64 divisors (see below), whose sum is σ = 3881358000. Its totient is φ = 641249280.

The previous prime is 1663960819. The next prime is 1663960841. The reversal of 1663960840 is 480693661.

It can be written as a sum of positive squares in 8 ways, for example, as 44542276 + 1619418564 = 6674^2 + 40242^2 .

It is not an unprimeable number, because it can be changed into a prime (1663960841) 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, 658780 + ... + 661300.

Almost surely, 2^1663960840 is an apocalyptic number.

1663960840 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 1663960840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1940679000).

1663960840 is an abundant number, since it is smaller than the sum of its proper divisors (2217397160).

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

1663960840 is a wasteful number, since it uses less digits than its factorization.

1663960840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3130 (or 3126 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 43.

The square root of 1663960840 is about 40791.6761116775. The cubic root of 1663960840 is about 1184.9891315091.

The spelling of 1663960840 in words is "one billion, six hundred sixty-three million, nine hundred sixty thousand, eight hundred forty".