1212121705 has 32 divisors (see below), whose sum is σ = 1503684000. Its totient is φ = 937728000.

The previous prime is 1212121699. The next prime is 1212121741. The reversal of 1212121705 is 5071212121.

It can be written as a sum of positive squares in 16 ways, for example, as 737448336 + 474673369 = 27156^2 + 21787^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1212121705 is a prime.

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, 6696715 + ... + 6696895.

It is an arithmetic number, because the mean of its divisors is an integer number (46990125).

Almost surely, 2^1212121705 is an apocalyptic number.

It is an amenable number.

1212121705 is a deficient number, since it is larger than the sum of its proper divisors (291562295).

1212121705 is a wasteful number, since it uses less digits than its factorization.

1212121705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525.

The product of its (nonzero) digits is 280, while the sum is 22.

The square root of 1212121705 is about 34815.5382695715. The cubic root of 1212121705 is about 1066.2247087793.

Adding to 1212121705 its reverse (5071212121), we get a palindrome (6283333826).

The spelling of 1212121705 in words is "one billion, two hundred twelve million, one hundred twenty-one thousand, seven hundred five".