1221212019 has 8 divisors (see below), whose sum is σ = 1667997072. Its totient is φ = 794284160.

The previous prime is 1221211991. The next prime is 1221212029. The reversal of 1221212019 is 9102121221.

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 1221212019 - 2¹⁵ = 1221179251 is a prime.

It is a super-2 number, since 2×1221212019² = 2982717590700112722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221211986 and 1221212004.

It is not an unprimeable number, because it can be changed into a prime (1221212029) 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, 4964154 + ... + 4964399.

It is an arithmetic number, because the mean of its divisors is an integer number (208499634).

Almost surely, 2^1221212019 is an apocalyptic number.

1221212019 is a deficient number, since it is larger than the sum of its proper divisors (446785053).

1221212019 is an equidigital number, since it uses as much as digits as its factorization.

1221212019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9928597.

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 1221212019 is about 34945.8440876737. The cubic root of 1221212019 is about 1068.8834595759.

The spelling of 1221212019 in words is "one billion, two hundred twenty-one million, two hundred twelve thousand, nineteen".