21020819954 has 32 divisors (see below), whose sum is σ = 32568022080. Its totient is φ = 10169736192.

The previous prime is 21020819951. The next prime is 21020819999. The reversal of 21020819954 is 45991802012.

It is not an unprimeable number, because it can be changed into a prime (21020819951) 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, 6631682 + ... + 6634850.

It is an arithmetic number, because the mean of its divisors is an integer number (1017750690).

Almost surely, 2^21020819954 is an apocalyptic number.

21020819954 is a deficient number, since it is larger than the sum of its proper divisors (11547202126).

21020819954 is a wasteful number, since it uses less digits than its factorization.

21020819954 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3914.

The product of its (nonzero) digits is 51840, while the sum is 41.

The spelling of 21020819954 in words is "twenty-one billion, twenty million, eight hundred nineteen thousand, nine hundred fifty-four".