43779721 has 2 divisors, whose sum is σ = 43779722. Its totient is φ = 43779720.

The previous prime is 43779661. The next prime is 43779727. The reversal of 43779721 is 12797734.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39200121 + 4579600 = 6261^2 + 2140^2 .

It is a cyclic number.

It is not a de Polignac number, because 43779721 - 2⁹ = 43779209 is a prime.

It is not a weakly prime, because it can be changed into another prime (43779727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21889860 + 21889861.

It is an arithmetic number, because the mean of its divisors is an integer number (21889861).

Almost surely, 2^43779721 is an apocalyptic number.

It is an amenable number.

43779721 is a deficient number, since it is larger than the sum of its proper divisors (1).

43779721 is an equidigital number, since it uses as much as digits as its factorization.

43779721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 74088, while the sum is 40.

The square root of 43779721 is about 6616.6245926454. The cubic root of 43779721 is about 352.4447100714. Note that the first 3 decimals are identical.

The spelling of 43779721 in words is "forty-three million, seven hundred seventy-nine thousand, seven hundred twenty-one".