143561921 has 2 divisors, whose sum is σ = 143561922. Its totient is φ = 143561920.

The previous prime is 143561917. The next prime is 143561933. The reversal of 143561921 is 129165341.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141871921 + 1690000 = 11911^2 + 1300^2 .

It is a cyclic number.

It is not a de Polignac number, because 143561921 - 2² = 143561917 is a prime.

It is a super-2 number, since 2×143561921² = 41220050322420482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (143561941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 71780960 + 71780961.

It is an arithmetic number, because the mean of its divisors is an integer number (71780961).

Almost surely, 2^143561921 is an apocalyptic number.

It is an amenable number.

143561921 is a deficient number, since it is larger than the sum of its proper divisors (1).

143561921 is an equidigital number, since it uses as much as digits as its factorization.

143561921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 32.

The square root of 143561921 is about 11981.7328045655. The cubic root of 143561921 is about 523.6162149583.

It can be divided in two parts, 14 and 3561921, that multiplied together give a palindrome (49866894).

The spelling of 143561921 in words is "one hundred forty-three million, five hundred sixty-one thousand, nine hundred twenty-one".