43197049921 has 9 divisors (see below), whose sum is σ = 43402324899. Its totient is φ = 42992744184.

The previous prime is 43197049919. The next prime is 43197049927. The reversal of 43197049921 is 12994079134.

The square root of 43197049921 is 207839.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 42942200625 + 254849296 = 207225^2 + 15964^2 .

It is not a de Polignac number, because 43197049921 - 2¹ = 43197049919 is a prime.

It is a super-2 number, since 2×43197049921² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43197049927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 63806235 + ... + 63806911.

Almost surely, 2^43197049921 is an apocalyptic number.

43197049921 is the 207839-th square number.

43197049921 is the 103920-th centered octagonal number.

It is an amenable number.

43197049921 is a deficient number, since it is larger than the sum of its proper divisors (205274978).

43197049921 is an frugal number, since it uses more digits than its factorization.

43197049921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1968 (or 984 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 49.

Multiplying 43197049921 by its sum of digits (49), we get a square (2116655446129 = 1454873²).

The spelling of 43197049921 in words is "forty-three billion, one hundred ninety-seven million, forty-nine thousand, nine hundred twenty-one".