21041897919 has 16 divisors (see below), whose sum is σ = 32177959680. Its totient is φ = 11981148480.

The previous prime is 21041897881. The next prime is 21041897939. The reversal of 21041897919 is 91979814012.

It is a happy number.

It is not a de Polignac number, because 21041897919 - 2¹³ = 21041889727 is a prime.

It is a super-2 number, since 2×21041897919² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21041897939) 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, 1777009 + ... + 1788810.

It is an arithmetic number, because the mean of its divisors is an integer number (2011122480).

Almost surely, 2^21041897919 is an apocalyptic number.

21041897919 is a deficient number, since it is larger than the sum of its proper divisors (11136061761).

21041897919 is a wasteful number, since it uses less digits than its factorization.

21041897919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3566110.

The product of its (nonzero) digits is 326592, while the sum is 51.

The spelling of 21041897919 in words is "twenty-one billion, forty-one million, eight hundred ninety-seven thousand, nine hundred nineteen".