1113437821 has 2 divisors, whose sum is σ = 1113437822. Its totient is φ = 1113437820.

The previous prime is 1113437789. The next prime is 1113437839. The reversal of 1113437821 is 1287343111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 713637796 + 399800025 = 26714^2 + 19995^2 .

It is an emirp because it is prime and its reverse (1287343111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1113437821 - 2⁵ = 1113437789 is a prime.

It is a super-4 number, since 4×1113437821⁴ (a number of 37 digits) contains 4444 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1113437891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 556718910 + 556718911.

It is an arithmetic number, because the mean of its divisors is an integer number (556718911).

Almost surely, 2^1113437821 is an apocalyptic number.

It is an amenable number.

1113437821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1113437821 is an equidigital number, since it uses as much as digits as its factorization.

1113437821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 31.

The square root of 1113437821 is about 33368.2157299428. The cubic root of 1113437821 is about 1036.4666274600.

The spelling of 1113437821 in words is "one billion, one hundred thirteen million, four hundred thirty-seven thousand, eight hundred twenty-one".