21471921628 has 6 divisors (see below), whose sum is σ = 37575862856. Its totient is φ = 10735960812.

The previous prime is 21471921619. The next prime is 21471921727. The reversal of 21471921628 is 82612917412.

It is a super-2 number, since 2×21471921628² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2683990200 + ... + 2683990207.

Almost surely, 2^21471921628 is an apocalyptic number.

It is an amenable number.

21471921628 is a deficient number, since it is larger than the sum of its proper divisors (16103941228).

21471921628 is a wasteful number, since it uses less digits than its factorization.

21471921628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5367980411 (or 5367980409 counting only the distinct ones).

The product of its digits is 96768, while the sum is 43.

The spelling of 21471921628 in words is "twenty-one billion, four hundred seventy-one million, nine hundred twenty-one thousand, six hundred twenty-eight".