1233520421 has 4 divisors (see below), whose sum is σ = 1409737632. Its totient is φ = 1057303212.

The previous prime is 1233520399. The next prime is 1233520439. The reversal of 1233520421 is 1240253321.

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: 1240253321 = 41 ⋅30250081.

It is a de Polignac number, because none of the positive numbers 2^k-1233520421 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1233520471) 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, 88108595 + ... + 88108608.

It is an arithmetic number, because the mean of its divisors is an integer number (352434408).

Almost surely, 2^1233520421 is an apocalyptic number.

It is an amenable number.

1233520421 is a deficient number, since it is larger than the sum of its proper divisors (176217211).

1233520421 is an equidigital number, since it uses as much as digits as its factorization.

1233520421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176217210.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 1233520421 is about 35121.5093781574. The cubic root of 1233520421 is about 1072.4624977333.

Adding to 1233520421 its reverse (1240253321), we get a palindrome (2473773742).

The spelling of 1233520421 in words is "one billion, two hundred thirty-three million, five hundred twenty thousand, four hundred twenty-one".