21890426 has 8 divisors (see below), whose sum is σ = 33251520. Its totient is φ = 10806588.

The previous prime is 21890423. The next prime is 21890461. The reversal of 21890426 is 62409812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21890426² = 958381500922952, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21890392 and 21890401.

It is not an unprimeable number, because it can be changed into a prime (21890423) 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, 69116 + ... + 69431.

It is an arithmetic number, because the mean of its divisors is an integer number (4156440).

Almost surely, 2^21890426 is an apocalyptic number.

21890426 is a deficient number, since it is larger than the sum of its proper divisors (11361094).

21890426 is a wasteful number, since it uses less digits than its factorization.

21890426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138628.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 21890426 is about 4678.7205516038. The cubic root of 21890426 is about 279.7379606280.

The spelling of 21890426 in words is "twenty-one million, eight hundred ninety thousand, four hundred twenty-six".