1623223921 has 4 divisors (see below), whose sum is σ = 1770789744. Its totient is φ = 1475658100.

The previous prime is 1623223867. The next prime is 1623223933. The reversal of 1623223921 is 1293223261.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1293223261 = 11 ⋅117565751.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1623223921 is a prime.

It is a super-2 number, since 2×1623223921² = 5269711795413228482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1623224921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73782895 + ... + 73782916.

It is an arithmetic number, because the mean of its divisors is an integer number (442697436).

Almost surely, 2^1623223921 is an apocalyptic number.

1623223921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1623223921 is a deficient number, since it is larger than the sum of its proper divisors (147565823).

1623223921 is a wasteful number, since it uses less digits than its factorization.

1623223921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147565822.

The product of its digits is 7776, while the sum is 31.

The square root of 1623223921 is about 40289.2531700452. The cubic root of 1623223921 is about 1175.2388640082.

The spelling of 1623223921 in words is "one billion, six hundred twenty-three million, two hundred twenty-three thousand, nine hundred twenty-one".