1243212013 has 4 divisors (see below), whose sum is σ = 1243284448. Its totient is φ = 1243139580.

The previous prime is 1243211999. The next prime is 1243212029. The reversal of 1243212013 is 3102123421.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 3102123421 = 6991 ⋅443731.

It is a cyclic number.

It is not a de Polignac number, because 1243212013 - 2¹³ = 1243203821 is a prime.

It is a super-2 number, since 2×1243212013² = 3091152218535024338, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243212053) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5698 + ... + 50188.

It is an arithmetic number, because the mean of its divisors is an integer number (310821112).

Almost surely, 2^1243212013 is an apocalyptic number.

It is an amenable number.

1243212013 is a deficient number, since it is larger than the sum of its proper divisors (72435).

1243212013 is an equidigital number, since it uses as much as digits as its factorization.

1243212013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72434.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 1243212013 is about 35259.2117467195. The cubic root of 1243212013 is about 1075.2639014616.

Adding to 1243212013 its reverse (3102123421), we get a palindrome (4345335434).

The spelling of 1243212013 in words is "one billion, two hundred forty-three million, two hundred twelve thousand, thirteen".