45178921 has 2 divisors, whose sum is σ = 45178922. Its totient is φ = 45178920.

The previous prime is 45178909. The next prime is 45178927. The reversal of 45178921 is 12987154.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44368921 + 810000 = 6661^2 + 900^2 .

It is a cyclic number.

It is not a de Polignac number, because 45178921 - 2¹³ = 45170729 is a prime.

It is a super-2 number, since 2×45178921² = 4082269805448482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (45178927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22589460 + 22589461.

It is an arithmetic number, because the mean of its divisors is an integer number (22589461).

Almost surely, 2^45178921 is an apocalyptic number.

It is an amenable number.

45178921 is a deficient number, since it is larger than the sum of its proper divisors (1).

45178921 is an equidigital number, since it uses as much as digits as its factorization.

45178921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 37.

The square root of 45178921 is about 6721.5266866985. The cubic root of 45178921 is about 356.1601166078.

The spelling of 45178921 in words is "forty-five million, one hundred seventy-eight thousand, nine hundred twenty-one".