21374091 has 16 divisors (see below), whose sum is σ = 31912320. Its totient is φ = 14138280.

The previous prime is 21374071. The next prime is 21374113. The reversal of 21374091 is 19047312.

It is not a de Polignac number, because 21374091 - 2²² = 17179787 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21374011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 516 + ... + 6558.

It is an arithmetic number, because the mean of its divisors is an integer number (1994520).

Almost surely, 2^21374091 is an apocalyptic number.

21374091 is a deficient number, since it is larger than the sum of its proper divisors (10538229).

21374091 is a wasteful number, since it uses less digits than its factorization.

21374091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6183 (or 6177 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21374091 is about 4623.2121950004. The cubic root of 21374091 is about 277.5210210518.

The spelling of 21374091 in words is "twenty-one million, three hundred seventy-four thousand, ninety-one".