21020978151612 has 96 divisors (see below), whose sum is σ = 54992194790400. Its totient is φ = 6943585372416.

The previous prime is 21020978151611. The next prime is 21020978151619. The reversal of 21020978151612 is 21615187902012.

21020978151612 is a `hidden beast` number, since 2 + 1 + 0 + 20 + 9 + 7 + 8 + 1 + 5 + 1 + 612 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020978151611) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 61325043 + ... + 61666869.

It is an arithmetic number, because the mean of its divisors is an integer number (572835362400).

Almost surely, 2^{21020978151612} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21020978151612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27496097395200).

21020978151612 is an abundant number, since it is smaller than the sum of its proper divisors (33971216638788).

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

21020978151612 is a wasteful number, since it uses less digits than its factorization.

21020978151612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346992 (or 346984 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 45.

The spelling of 21020978151612 in words is "twenty-one trillion, twenty billion, nine hundred seventy-eight million, one hundred fifty-one thousand, six hundred twelve".