1212121109 has 8 divisors (see below), whose sum is σ = 1248640800. Its totient is φ = 1175980176.

The previous prime is 1212121069. The next prime is 1212121121. The reversal of 1212121109 is 9011212121.

1212121109 = T₇₄₈₇ + T₇₄₈₈ + ... + T₇₅₂₉.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1212121109 - 2¹² = 1212117013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212121129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88187 + ... + 101000.

It is an arithmetic number, because the mean of its divisors is an integer number (156080100).

Almost surely, 2^1212121109 is an apocalyptic number.

It is an amenable number.

1212121109 is a deficient number, since it is larger than the sum of its proper divisors (36519691).

1212121109 is a wasteful number, since it uses less digits than its factorization.

1212121109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189379.

The product of its (nonzero) digits is 72, while the sum is 20.

The square root of 1212121109 is about 34815.5297101739. The cubic root of 1212121109 is about 1066.2245340251.

The spelling of 1212121109 in words is "one billion, two hundred twelve million, one hundred twenty-one thousand, one hundred nine".