1212156404 has 12 divisors (see below), whose sum is σ = 2130379524. Its totient is φ = 603476544.

The previous prime is 1212156401. The next prime is 1212156443. The reversal of 1212156404 is 4046512121.

It can be written as a sum of positive squares in 2 ways, for example, as 758892304 + 453264100 = 27548^2 + 21290^2 .

It is a super-2 number, since 2×1212156404² = 2938646295516422432, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212156401) 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, 649367 + ... + 651230.

It is an arithmetic number, because the mean of its divisors is an integer number (177531627).

Almost surely, 2^1212156404 is an apocalyptic number.

It is an amenable number.

1212156404 is a deficient number, since it is larger than the sum of its proper divisors (918223120).

1212156404 is a wasteful number, since it uses less digits than its factorization.

1212156404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1300834 (or 1300832 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 1212156404 is about 34816.0365923521. The cubic root of 1212156404 is about 1066.2348828341.

Adding to 1212156404 its reverse (4046512121), we get a palindrome (5258668525).

The spelling of 1212156404 in words is "one billion, two hundred twelve million, one hundred fifty-six thousand, four hundred four".