21453631472878 has 16 divisors (see below), whose sum is σ = 37170997846704. Its totient is φ = 9178024159360.

The previous prime is 21453631472863. The next prime is 21453631472921. The reversal of 21453631472878 is 87827413635412.

It is a super-2 number, since 2×21453631472878² (a number of 27 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 in 7 ways as a sum of consecutive naturals, for example, 28681325125 + ... + 28681325872.

It is an arithmetic number, because the mean of its divisors is an integer number (2323187365419).

Almost surely, 2^{21453631472878} is an apocalyptic number.

21453631472878 is a deficient number, since it is larger than the sum of its proper divisors (15717366373826).

21453631472878 is a wasteful number, since it uses less digits than its factorization.

21453631472878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57362651027.

The product of its digits is 54190080, while the sum is 61.

The spelling of 21453631472878 in words is "twenty-one trillion, four hundred fifty-three billion, six hundred thirty-one million, four hundred seventy-two thousand, eight hundred seventy-eight".