26691021 has 12 divisors (see below), whose sum is σ = 44061472. Its totient is φ = 15251976.

The previous prime is 26691013. The next prime is 26691047. The reversal of 26691021 is 12019662.

It is not a de Polignac number, because 26691021 - 2³ = 26691013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26691001) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 211771 + ... + 211896.

Almost surely, 2^26691021 is an apocalyptic number.

26691021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

26691021 is a deficient number, since it is larger than the sum of its proper divisors (17370451).

26691021 is a wasteful number, since it uses less digits than its factorization.

26691021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423680 (or 423677 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 26691021 is about 5166.3353549687. The cubic root of 26691021 is about 298.8512401171.

The spelling of 26691021 in words is "twenty-six million, six hundred ninety-one thousand, twenty-one".