45278521 has 2 divisors, whose sum is σ = 45278522. Its totient is φ = 45278520.

The previous prime is 45278503. The next prime is 45278537. The reversal of 45278521 is 12587254.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25351225 + 19927296 = 5035^2 + 4464^2 .

It is a cyclic number.

It is not a de Polignac number, because 45278521 - 2⁵ = 45278489 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (45278561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22639260 + 22639261.

It is an arithmetic number, because the mean of its divisors is an integer number (22639261).

Almost surely, 2^45278521 is an apocalyptic number.

It is an amenable number.

45278521 is a deficient number, since it is larger than the sum of its proper divisors (1).

45278521 is an equidigital number, since it uses as much as digits as its factorization.

45278521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22400, while the sum is 34.

The square root of 45278521 is about 6728.9316388265. The cubic root of 45278521 is about 356.4216509013.

Adding to 45278521 its product of digits (22400), we get a triangular number (45300921 = T₉₅₁₈).

The spelling of 45278521 in words is "forty-five million, two hundred seventy-eight thousand, five hundred twenty-one".