1821229131 has 16 divisors (see below), whose sum is σ = 2453255424. Its totient is φ = 1201699104.

The previous prime is 1821229129. The next prime is 1821229177. The reversal of 1821229131 is 1319221281.

It is not a de Polignac number, because 1821229131 - 2¹ = 1821229129 is a prime.

It is a super-2 number, since 2×1821229131² = 6633751095206030322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1821229031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 493465 + ... + 497141.

It is an arithmetic number, because the mean of its divisors is an integer number (153328464).

Almost surely, 2^1821229131 is an apocalyptic number.

1821229131 is a deficient number, since it is larger than the sum of its proper divisors (632026293).

1821229131 is a wasteful number, since it uses less digits than its factorization.

1821229131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5330.

The product of its digits is 1728, while the sum is 30.

The square root of 1821229131 is about 42675.8612215383. The cubic root of 1821229131 is about 1221.2039380557.

The spelling of 1821229131 in words is "one billion, eight hundred twenty-one million, two hundred twenty-nine thousand, one hundred thirty-one".