21934278 has 12 divisors (see below), whose sum is σ = 47524308. Its totient is φ = 7311420.

The previous prime is 21934277. The next prime is 21934279. The reversal of 21934278 is 87243912.

It is an interprime number because it is at equal distance from previous prime (21934277) and next prime (21934279).

It is a super-2 number, since 2×21934278² = 962225102762568, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21934277) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 609268 + ... + 609303.

It is an arithmetic number, because the mean of its divisors is an integer number (3960359).

Almost surely, 2^21934278 is an apocalyptic number.

21934278 is an abundant number, since it is smaller than the sum of its proper divisors (25590030).

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

21934278 is a wasteful number, since it uses less digits than its factorization.

21934278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1218579 (or 1218576 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 21934278 is about 4683.4045308942. The cubic root of 21934278 is about 279.9246310750.

The spelling of 21934278 in words is "twenty-one million, nine hundred thirty-four thousand, two hundred seventy-eight".