12721961 has 12 divisors (see below), whose sum is σ = 14841792. Its totient is φ = 10682256.

The previous prime is 12721939. The next prime is 12721999. The reversal of 12721961 is 16912721.

It is not a de Polignac number, because 12721961 - 2¹⁸ = 12459817 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12721361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19340 + ... + 19986.

It is an arithmetic number, because the mean of its divisors is an integer number (1236816).

Almost surely, 2^12721961 is an apocalyptic number.

It is an amenable number.

12721961 is a deficient number, since it is larger than the sum of its proper divisors (2119831).

12721961 is an frugal number, since it uses more digits than its factorization.

12721961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 760 (or 707 counting only the distinct ones).

The product of its digits is 1512, while the sum is 29.

The square root of 12721961 is about 3566.7858079789. The cubic root of 12721961 is about 233.4450591927.

The spelling of 12721961 in words is "twelve million, seven hundred twenty-one thousand, nine hundred sixty-one".