420821437 has 2 divisors, whose sum is σ = 420821438. Its totient is φ = 420821436.

The previous prime is 420821419. The next prime is 420821441. The reversal of 420821437 is 734128024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 238733401 + 182088036 = 15451^2 + 13494^2 .

It is a cyclic number.

It is not a de Polignac number, because 420821437 - 2¹⁹ = 420297149 is a prime.

It is a super-4 number, since 4×420821437⁴ (a number of 36 digits) contains 4444 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 420821399 and 420821408.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (420825437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210410718 + 210410719.

It is an arithmetic number, because the mean of its divisors is an integer number (210410719).

Almost surely, 2^420821437 is an apocalyptic number.

It is an amenable number.

420821437 is a deficient number, since it is larger than the sum of its proper divisors (1).

420821437 is an equidigital number, since it uses as much as digits as its factorization.

420821437 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10752, while the sum is 31.

The square root of 420821437 is about 20513.9327531315. The cubic root of 420821437 is about 749.3751459248.

The spelling of 420821437 in words is "four hundred twenty million, eight hundred twenty-one thousand, four hundred thirty-seven".