21154535621240 has 384 divisors, whose sum is σ = 58650696561600. Its totient is φ = 6835283804160.

The previous prime is 21154535621209. The next prime is 21154535621251. The reversal of 21154535621240 is 4212653545112.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5907436250 + ... + 5907439830.

Almost surely, 2^{21154535621240} is an apocalyptic number.

21154535621240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21154535621240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29325348280800).

21154535621240 is an abundant number, since it is smaller than the sum of its proper divisors (37496160940360).

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

21154535621240 is a wasteful number, since it uses less digits than its factorization.

21154535621240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6095 (or 6084 counting only the distinct ones).

The product of its (nonzero) digits is 288000, while the sum is 41.

The spelling of 21154535621240 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred thirty-five million, six hundred twenty-one thousand, two hundred forty".