1243161640 has 128 divisors (see below), whose sum is σ = 3429216000. Its totient is φ = 396085248.

The previous prime is 1243161637. The next prime is 1243161653. The reversal of 1243161640 is 461613421.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 1243161599 and 1243161608.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 279756 + ... + 284164.

It is an arithmetic number, because the mean of its divisors is an integer number (26790750).

Almost surely, 2^1243161640 is an apocalyptic number.

1243161640 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 1243161640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1714608000).

1243161640 is an abundant number, since it is smaller than the sum of its proper divisors (2186054360).

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

1243161640 is a wasteful number, since it uses less digits than its factorization.

1243161640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4499 (or 4495 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 1243161640 is about 35258.4974155167. The cubic root of 1243161640 is about 1075.2493785968.

The spelling of 1243161640 in words is "one billion, two hundred forty-three million, one hundred sixty-one thousand, six hundred forty".