21121211010464 has 48 divisors (see below), whose sum is σ = 42322800088800. Its totient is φ = 10372864998144.

The previous prime is 21121211010463. The next prime is 21121211010467. The reversal of 21121211010464 is 46401011212112.

It is a happy number.

It is a super-2 number, since 2×21121211010464² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121211010463) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2471279 + ... + 6953390.

It is an arithmetic number, because the mean of its divisors is an integer number (881725001850).

Almost surely, 2^{21121211010464} is an apocalyptic number.

It is an amenable number.

21121211010464 is an abundant number, since it is smaller than the sum of its proper divisors (21201589078336).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21121211010464 is a wasteful number, since it uses less digits than its factorization.

21121211010464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9425925 (or 9425917 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 26.

Adding to 21121211010464 its reverse (46401011212112), we get a palindrome (67522222222576).

The spelling of 21121211010464 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred eleven million, ten thousand, four hundred sixty-four".