21494788 has 24 divisors (see below), whose sum is σ = 44860032. Its totient is φ = 8811264.

The previous prime is 21494779. The next prime is 21494789. The reversal of 21494788 is 88749412.

It is a super-2 number, since 2×21494788² = 924051822329888, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21494789) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16045 + ... + 17332.

It is an arithmetic number, because the mean of its divisors is an integer number (1869168).

Almost surely, 2^21494788 is an apocalyptic number.

21494788 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21494788 is an abundant number, since it is smaller than the sum of its proper divisors (23365244).

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

21494788 is a wasteful number, since it uses less digits than its factorization.

21494788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33411 (or 33409 counting only the distinct ones).

The product of its digits is 129024, while the sum is 43.

The square root of 21494788 is about 4636.2471892685. The cubic root of 21494788 is about 278.0424171427.

The spelling of 21494788 in words is "twenty-one million, four hundred ninety-four thousand, seven hundred eighty-eight".