45451993 has 4 divisors (see below), whose sum is σ = 45469620. Its totient is φ = 45434368.

The previous prime is 45451957. The next prime is 45452023. The reversal of 45451993 is 39915454.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 39915454 = 2 ⋅19957727.

It can be written as a sum of positive squares in 2 ways, for example, as 30614089 + 14837904 = 5533^2 + 3852^2 .

It is a cyclic number.

It is not a de Polignac number, because 45451993 - 2⁹ = 45451481 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (45454993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4108 + ... + 10381.

It is an arithmetic number, because the mean of its divisors is an integer number (11367405).

Almost surely, 2^45451993 is an apocalyptic number.

It is an amenable number.

45451993 is a deficient number, since it is larger than the sum of its proper divisors (17627).

45451993 is a wasteful number, since it uses less digits than its factorization.

45451993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17626.

The product of its digits is 97200, while the sum is 40.

The square root of 45451993 is about 6741.8093268795. The cubic root of 45451993 is about 356.8762474921.

The spelling of 45451993 in words is "forty-five million, four hundred fifty-one thousand, nine hundred ninety-three".