921811449 has 16 divisors (see below), whose sum is σ = 1324568000. Its totient is φ = 566865216.

The previous prime is 921811447. The next prime is 921811453. The reversal of 921811449 is 944118129.

It is not a de Polignac number, because 921811449 - 2¹ = 921811447 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (921811447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52782 + ... + 68040.

It is an arithmetic number, because the mean of its divisors is an integer number (82785500).

Almost surely, 2^921811449 is an apocalyptic number.

It is an amenable number.

921811449 is a deficient number, since it is larger than the sum of its proper divisors (402756551).

921811449 is a wasteful number, since it uses less digits than its factorization.

921811449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16824.

The product of its digits is 20736, while the sum is 39.

The square root of 921811449 is about 30361.3479443848. The cubic root of 921811449 is about 973.2267392677.

The spelling of 921811449 in words is "nine hundred twenty-one million, eight hundred eleven thousand, four hundred forty-nine".