1821864961 has 8 divisors (see below), whose sum is σ = 2103597440. Its totient is φ = 1545499008.

The previous prime is 1821864949. The next prime is 1821864997. The reversal of 1821864961 is 1694681281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1821864961 - 2²¹ = 1819767809 is a prime.

It is a super-2 number, since 2×1821864961² = 6638383872239063042, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1821864931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1340901 + ... + 1342258.

It is an arithmetic number, because the mean of its divisors is an integer number (262949680).

Almost surely, 2^1821864961 is an apocalyptic number.

It is an amenable number.

1821864961 is a deficient number, since it is larger than the sum of its proper divisors (281732479).

1821864961 is an equidigital number, since it uses as much as digits as its factorization.

1821864961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2683263.

The product of its digits is 165888, while the sum is 46.

The square root of 1821864961 is about 42683.3100989134. The cubic root of 1821864961 is about 1221.3460376489.

The spelling of 1821864961 in words is "one billion, eight hundred twenty-one million, eight hundred sixty-four thousand, nine hundred sixty-one".