21121990945672 has 64 divisors (see below), whose sum is σ = 41717668608000. Its totient is φ = 10012237756416.

The previous prime is 21121990945669. The next prime is 21121990945697. The reversal of 21121990945672 is 27654909912112.

It is a super-2 number, since 2×21121990945672² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (58).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 837222 + ... + 6553237.

It is an arithmetic number, because the mean of its divisors is an integer number (651838572000).

Almost surely, 2^{21121990945672} is an apocalyptic number.

It is an amenable number.

21121990945672 is a deficient number, since it is larger than the sum of its proper divisors (20595677662328).

21121990945672 is a wasteful number, since it uses less digits than its factorization.

21121990945672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7390718 (or 7390714 counting only the distinct ones).

The product of its (nonzero) digits is 4898880, while the sum is 58.

The spelling of 21121990945672 in words is "twenty-one trillion, one hundred twenty-one billion, nine hundred ninety million, nine hundred forty-five thousand, six hundred seventy-two".