1815223437 has 6 divisors (see below), whose sum is σ = 2621989422. Its totient is φ = 1210148952.

The previous prime is 1815223351. The next prime is 1815223451. The reversal of 1815223437 is 7343225181.

It can be written as a sum of positive squares in only one way, i.e., 1553463396 + 261760041 = 39414^2 + 16179^2 .

It is not a de Polignac number, because 1815223437 - 2⁷ = 1815223309 is a prime.

It is a super-2 number, since 2×1815223437² = 6590072252468185938, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1815223537) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 100845738 + ... + 100845755.

It is an arithmetic number, because the mean of its divisors is an integer number (436998237).

Almost surely, 2^1815223437 is an apocalyptic number.

It is an amenable number.

1815223437 is a deficient number, since it is larger than the sum of its proper divisors (806765985).

1815223437 is a wasteful number, since it uses less digits than its factorization.

1815223437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201691499 (or 201691496 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 1815223437 is about 42605.4390541865. The cubic root of 1815223437 is about 1219.8601104945.

The spelling of 1815223437 in words is "one billion, eight hundred fifteen million, two hundred twenty-three thousand, four hundred thirty-seven".