21151064 has 16 divisors (see below), whose sum is σ = 43263720. Its totient is φ = 9614080.

The previous prime is 21151061. The next prime is 21151069. The reversal of 21151064 is 46015112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21151061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120089 + ... + 120264.

Almost surely, 2^21151064 is an apocalyptic number.

It is an amenable number.

21151064 is an abundant number, since it is smaller than the sum of its proper divisors (22112656).

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

21151064 is a wasteful number, since it uses less digits than its factorization.

21151064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240370 (or 240366 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 21151064 is about 4599.0285930835. The cubic root of 21151064 is about 276.5523838895.

Adding to 21151064 its reverse (46015112), we get a palindrome (67166176).

The spelling of 21151064 in words is "twenty-one million, one hundred fifty-one thousand, sixty-four".