42901721 has 2 divisors, whose sum is σ = 42901722. Its totient is φ = 42901720.

The previous prime is 42901709. The next prime is 42901769. The reversal of 42901721 is 12710924.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39438400 + 3463321 = 6280^2 + 1861^2 .

It is a cyclic number.

It is not a de Polignac number, because 42901721 - 2⁶ = 42901657 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (42901021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21450860 + 21450861.

It is an arithmetic number, because the mean of its divisors is an integer number (21450861).

Almost surely, 2^42901721 is an apocalyptic number.

It is an amenable number.

42901721 is a deficient number, since it is larger than the sum of its proper divisors (1).

42901721 is an equidigital number, since it uses as much as digits as its factorization.

42901721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 42901721 is about 6549.9405340812. The cubic root of 42901721 is about 350.0726951042.

The spelling of 42901721 in words is "forty-two million, nine hundred one thousand, seven hundred twenty-one".