40872421 has 2 divisors, whose sum is σ = 40872422. Its totient is φ = 40872420.

The previous prime is 40872409. The next prime is 40872431. The reversal of 40872421 is 12427804.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25553025 + 15319396 = 5055^2 + 3914^2 .

It is a cyclic number.

It is not a de Polignac number, because 40872421 - 2⁵ = 40872389 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 40872421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40872431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20436210 + 20436211.

It is an arithmetic number, because the mean of its divisors is an integer number (20436211).

Almost surely, 2^40872421 is an apocalyptic number.

It is an amenable number.

40872421 is a deficient number, since it is larger than the sum of its proper divisors (1).

40872421 is an equidigital number, since it uses as much as digits as its factorization.

40872421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3584, while the sum is 28.

The square root of 40872421 is about 6393.1542293300. The cubic root of 40872421 is about 344.4636937984.

The spelling of 40872421 in words is "forty million, eight hundred seventy-two thousand, four hundred twenty-one".