521223945 has 16 divisors (see below), whose sum is σ = 909772992. Its totient is φ = 252714560.

The previous prime is 521223943. The next prime is 521223949. The reversal of 521223945 is 549322125.

It is not a de Polignac number, because 521223945 - 2¹ = 521223943 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (521223943) 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, 1579302 + ... + 1579631.

It is an arithmetic number, because the mean of its divisors is an integer number (56860812).

Almost surely, 2^521223945 is an apocalyptic number.

521223945 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

521223945 is a deficient number, since it is larger than the sum of its proper divisors (388549047).

521223945 is a wasteful number, since it uses less digits than its factorization.

521223945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3158952.

The product of its digits is 21600, while the sum is 33.

The square root of 521223945 is about 22830.3294982793. The cubic root of 521223945 is about 804.7755736659.

The spelling of 521223945 in words is "five hundred twenty-one million, two hundred twenty-three thousand, nine hundred forty-five".