1821893949 has 36 divisors (see below), whose sum is σ = 2746283904. Its totient is φ = 1163603232.

The previous prime is 1821893939. The next prime is 1821893959. The reversal of 1821893949 is 9493981281.

It is an interprime number because it is at equal distance from previous prime (1821893939) and next prime (1821893959).

It is not a de Polignac number, because 1821893949 - 2⁴ = 1821893933 is a prime.

It is a super-2 number, since 2×1821893949² = 6638595122805629202, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1821893895 and 1821893904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821893929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 824404 + ... + 826610.

It is an arithmetic number, because the mean of its divisors is an integer number (76285664).

Almost surely, 2^1821893949 is an apocalyptic number.

It is an amenable number.

1821893949 is a deficient number, since it is larger than the sum of its proper divisors (924389955).

1821893949 is a wasteful number, since it uses less digits than its factorization.

1821893949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2354 (or 2314 counting only the distinct ones).

The product of its digits is 1119744, while the sum is 54.

The square root of 1821893949 is about 42683.6496682278. The cubic root of 1821893949 is about 1221.3525152953.

The spelling of 1821893949 in words is "one billion, eight hundred twenty-one million, eight hundred ninety-three thousand, nine hundred forty-nine".