2621643381 has 16 divisors (see below), whose sum is σ = 4438761600. Its totient is φ = 1498081824.

The previous prime is 2621643377. The next prime is 2621643383. The reversal of 2621643381 is 1833461262.

2621643381 is a `hidden beast` number, since 2 + 6 + 2 + 1 + 643 + 3 + 8 + 1 = 666.

It is not a de Polignac number, because 2621643381 - 2² = 2621643377 is a prime.

It is a super-2 number, since 2×2621643381² = 13746028034282222322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2621643383) 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, 6935376 + ... + 6935753.

It is an arithmetic number, because the mean of its divisors is an integer number (277422600).

Almost surely, 2^2621643381 is an apocalyptic number.

2621643381 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2621643381 is a deficient number, since it is larger than the sum of its proper divisors (1817118219).

2621643381 is a wasteful number, since it uses less digits than its factorization.

2621643381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13871145 (or 13871139 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 2621643381 is about 51201.9861040565. The cubic root of 2621643381 is about 1378.8738591522.

The spelling of 2621643381 in words is "two billion, six hundred twenty-one million, six hundred forty-three thousand, three hundred eighty-one".