40206421 has 2 divisors, whose sum is σ = 40206422. Its totient is φ = 40206420.

The previous prime is 40206409. The next prime is 40206431. The reversal of 40206421 is 12460204.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36360900 + 3845521 = 6030^2 + 1961^2 .

It is a cyclic number.

It is not a de Polignac number, because 40206421 - 2⁷ = 40206293 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40206401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20103210 + 20103211.

It is an arithmetic number, because the mean of its divisors is an integer number (20103211).

Almost surely, 2^40206421 is an apocalyptic number.

It is an amenable number.

40206421 is a deficient number, since it is larger than the sum of its proper divisors (1).

40206421 is an equidigital number, since it uses as much as digits as its factorization.

40206421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 40206421 is about 6340.8533337399. The cubic root of 40206421 is about 342.5824718370.

Adding to 40206421 its reverse (12460204), we get a palindrome (52666625).

The spelling of 40206421 in words is "forty million, two hundred six thousand, four hundred twenty-one".