40617821 has 2 divisors, whose sum is σ = 40617822. Its totient is φ = 40617820.

The previous prime is 40617817. The next prime is 40617827. The reversal of 40617821 is 12871604.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31248100 + 9369721 = 5590^2 + 3061^2 .

It is a cyclic number.

It is not a de Polignac number, because 40617821 - 2² = 40617817 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40617827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20308910 + 20308911.

It is an arithmetic number, because the mean of its divisors is an integer number (20308911).

Almost surely, 2^40617821 is an apocalyptic number.

It is an amenable number.

40617821 is a deficient number, since it is larger than the sum of its proper divisors (1).

40617821 is an equidigital number, since it uses as much as digits as its factorization.

40617821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 40617821 is about 6373.2112000153. The cubic root of 40617821 is about 343.7469660999.

The spelling of 40617821 in words is "forty million, six hundred seventeen thousand, eight hundred twenty-one".