42921457 has 2 divisors, whose sum is σ = 42921458. Its totient is φ = 42921456.

The previous prime is 42921451. The next prime is 42921509. The reversal of 42921457 is 75412924.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27625536 + 15295921 = 5256^2 + 3911^2 .

It is a cyclic number.

It is not a de Polignac number, because 42921457 - 2¹⁵ = 42888689 is a prime.

It is not a weakly prime, because it can be changed into another prime (42921451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21460728 + 21460729.

It is an arithmetic number, because the mean of its divisors is an integer number (21460729).

Almost surely, 2^42921457 is an apocalyptic number.

It is an amenable number.

42921457 is a deficient number, since it is larger than the sum of its proper divisors (1).

42921457 is an equidigital number, since it uses as much as digits as its factorization.

42921457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 34.

The square root of 42921457 is about 6551.4469394173. The cubic root of 42921457 is about 350.1263679746.

The spelling of 42921457 in words is "forty-two million, nine hundred twenty-one thousand, four hundred fifty-seven".