21034689690 has 128 divisors (see below), whose sum is σ = 59138906112. Its totient is φ = 4688006400.

The previous prime is 21034689673. The next prime is 21034689691. The reversal of 21034689690 is 9698643012.

It is a super-2 number, since 2×21034689690² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21034689691) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6328369 + ... + 6331691.

It is an arithmetic number, because the mean of its divisors is an integer number (462022704).

Almost surely, 2^21034689690 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21034689690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29569453056).

21034689690 is an abundant number, since it is smaller than the sum of its proper divisors (38104216422).

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

21034689690 is a wasteful number, since it uses less digits than its factorization.

21034689690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4084.

The product of its (nonzero) digits is 559872, while the sum is 48.

The spelling of 21034689690 in words is "twenty-one billion, thirty-four million, six hundred eighty-nine thousand, six hundred ninety".