121210511409 has 81 divisors (see below), whose sum is σ = 193730160897. Its totient is φ = 72995150592.

The previous prime is 121210511369. The next prime is 121210511413. The reversal of 121210511409 is 904115012121.

The square root of 121210511409 is 348153.

It is a perfect power (a square), and thus also a powerful number.

121210511409 is a `hidden beast` number, since 121 + 21 + 0 + 511 + 4 + 0 + 9 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 90452367009 + 30758144400 = 300753^2 + 175380^2 .

It is not a de Polignac number, because 121210511409 - 2⁷ = 121210511281 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121210511459) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 1072659337 + ... + 1072659449.

Almost surely, 2^121210511409 is an apocalyptic number.

121210511409 is the 348153-rd square number.

121210511409 is the 174077-th centered octagonal number.

It is an amenable number.

121210511409 is a deficient number, since it is larger than the sum of its proper divisors (72519649488).

121210511409 is an equidigital number, since it uses as much as digits as its factorization.

121210511409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416 (or 208 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The spelling of 121210511409 in words is "one hundred twenty-one billion, two hundred ten million, five hundred eleven thousand, four hundred nine".