1213121002 has 4 divisors (see below), whose sum is σ = 1819681506. Its totient is φ = 606560500.

The previous prime is 1213120973. The next prime is 1213121009. The reversal of 1213121002 is 2001213121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2001213121 = 29 ⋅69007349.

It can be written as a sum of positive squares in only one way, i.e., 942551401 + 270569601 = 30701^2 + 16449^2 .

It is not an unprimeable number, because it can be changed into a prime (1213121009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 303280249 + ... + 303280252.

Almost surely, 2^1213121002 is an apocalyptic number.

1213121002 is a deficient number, since it is larger than the sum of its proper divisors (606560504).

1213121002 is an equidigital number, since it uses as much as digits as its factorization.

1213121002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 606560503.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1213121002 is about 34829.8866205447. The cubic root of 1213121002 is about 1066.5176338442.

Adding to 1213121002 its reverse (2001213121), we get a palindrome (3214334123).

It can be divided in two parts, 12131 and 21002, that added together give a palindrome (33133).

The spelling of 1213121002 in words is "one billion, two hundred thirteen million, one hundred twenty-one thousand, two".