20994984381 has 24 divisors (see below), whose sum is σ = 32652491200. Its totient is φ = 11994477936.

The previous prime is 20994984347. The next prime is 20994984421. The reversal of 20994984381 is 18348949902.

It is not a de Polignac number, because 20994984381 - 2⁷ = 20994984253 is a prime.

It is a super-2 number, since 2×20994984381² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20994984301) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4645735 + ... + 4650251.

Almost surely, 2^20994984381 is an apocalyptic number.

20994984381 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20994984381 is a deficient number, since it is larger than the sum of its proper divisors (11657506819).

20994984381 is an frugal number, since it uses more digits than its factorization.

20994984381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9058 (or 4527 counting only the distinct ones).

The product of its (nonzero) digits is 4478976, while the sum is 57.

The spelling of 20994984381 in words is "twenty billion, nine hundred ninety-four million, nine hundred eighty-four thousand, three hundred eighty-one".