21070989540 has 192 divisors, whose sum is σ = 70612254720. Its totient is φ = 5201159040.

The previous prime is 21070989539. The next prime is 21070989551. The reversal of 21070989540 is 4598907012.

21070989540 is a `hidden beast` number, since 2 + 10 + 7 + 0 + 98 + 9 + 540 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 357657 + ... + 412383.

It is an arithmetic number, because the mean of its divisors is an integer number (367772160).

Almost surely, 2^21070989540 is an apocalyptic number.

21070989540 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 21070989540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35306127360).

21070989540 is an abundant number, since it is smaller than the sum of its proper divisors (49541265180).

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

21070989540 is a wasteful number, since it uses less digits than its factorization.

21070989540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54799 (or 54791 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The spelling of 21070989540 in words is "twenty-one billion, seventy million, nine hundred eighty-nine thousand, five hundred forty".