21097627980 has 384 divisors, whose sum is σ = 74213314560. Its totient is φ = 4399349760.

The previous prime is 21097627939. The next prime is 21097628021. The reversal of 21097627980 is 8972679012.

It is an interprime number because it is at equal distance from previous prime (21097627939) and next prime (21097628021).

It is a Harshad number since it is a multiple of its sum of digits (51).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 15898077 + ... + 15899403.

It is an arithmetic number, because the mean of its divisors is an integer number (193263840).

Almost surely, 2^21097627980 is an apocalyptic number.

21097627980 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 21097627980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37106657280).

21097627980 is an abundant number, since it is smaller than the sum of its proper divisors (53115686580).

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

21097627980 is a wasteful number, since it uses less digits than its factorization.

21097627980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1489 (or 1487 counting only the distinct ones).

The product of its (nonzero) digits is 762048, while the sum is 51.

The spelling of 21097627980 in words is "twenty-one billion, ninety-seven million, six hundred twenty-seven thousand, nine hundred eighty".