451778921 has 16 divisors (see below), whose sum is σ = 497968128. Its totient is φ = 406467600.

The previous prime is 451778911. The next prime is 451778933. The reversal of 451778921 is 129877154.

It is a de Polignac number, because none of the positive numbers 2^k-451778921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (451778911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 607676 + ... + 608418.

It is an arithmetic number, because the mean of its divisors is an integer number (31123008).

Almost surely, 2^451778921 is an apocalyptic number.

It is an amenable number.

451778921 is a deficient number, since it is larger than the sum of its proper divisors (46189207).

451778921 is a wasteful number, since it uses less digits than its factorization.

451778921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1252.

The product of its digits is 141120, while the sum is 44.

The square root of 451778921 is about 21255.0916488262. The cubic root of 451778921 is about 767.3178853983.

It can be divided in two parts, 4517 and 78921, that added together give a palindrome (83438).

The spelling of 451778921 in words is "four hundred fifty-one million, seven hundred seventy-eight thousand, nine hundred twenty-one".