1305121020 has 192 divisors, whose sum is σ = 4504550400. Its totient is φ = 275650560.

The previous prime is 1305120997. The next prime is 1305121043. The reversal of 1305121020 is 201215031.

It is an interprime number because it is at equal distance from previous prime (1305120997) and next prime (1305121043).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 325186 + ... + 329174.

It is an arithmetic number, because the mean of its divisors is an integer number (23461200).

Almost surely, 2^1305121020 is an apocalyptic number.

1305121020 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 1305121020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2252275200).

1305121020 is an abundant number, since it is smaller than the sum of its proper divisors (3199429380).

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

1305121020 is a wasteful number, since it uses less digits than its factorization.

1305121020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4068 (or 4066 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 1305121020 is about 36126.4587248737. The cubic root of 1305121020 is about 1092.8240938115.

Adding to 1305121020 its reverse (201215031), we get a palindrome (1506336051).

The spelling of 1305121020 in words is "one billion, three hundred five million, one hundred twenty-one thousand, twenty".