1211013520 has 20 divisors (see below), whose sum is σ = 2815606620. Its totient is φ = 484405376.

The previous prime is 1211013509. The next prime is 1211013593. The reversal of 1211013520 is 253101121.

It can be written as a sum of positive squares in 2 ways, for example, as 925133056 + 285880464 = 30416^2 + 16908^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 1211013494 and 1211013503.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7568755 + ... + 7568914.

It is an arithmetic number, because the mean of its divisors is an integer number (140780331).

Almost surely, 2^1211013520 is an apocalyptic number.

1211013520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211013520 is an abundant number, since it is smaller than the sum of its proper divisors (1604593100).

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

1211013520 is a wasteful number, since it uses less digits than its factorization.

1211013520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15137682 (or 15137676 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 1211013520 is about 34799.6195381501. The cubic root of 1211013520 is about 1065.8996769246.

Adding to 1211013520 its reverse (253101121), we get a palindrome (1464114641).

The spelling of 1211013520 in words is "one billion, two hundred eleven million, thirteen thousand, five hundred twenty".