21147099 has 16 divisors (see below), whose sum is σ = 30552192. Its totient is φ = 12958848.

The previous prime is 21147083. The next prime is 21147107. The reversal of 21147099 is 99074112.

It is not a de Polignac number, because 21147099 - 2⁴ = 21147083 is a prime.

It is a super-2 number, since 2×21147099² = 894399592231602, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21147029) 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, 2629 + ... + 7014.

It is an arithmetic number, because the mean of its divisors is an integer number (1909512).

Almost surely, 2^21147099 is an apocalyptic number.

21147099 is a deficient number, since it is larger than the sum of its proper divisors (9405093).

21147099 is a wasteful number, since it uses less digits than its factorization.

21147099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9706.

The product of its (nonzero) digits is 4536, while the sum is 33.

The square root of 21147099 is about 4598.5975035874. The cubic root of 21147099 is about 276.5351018790.

The spelling of 21147099 in words is "twenty-one million, one hundred forty-seven thousand, ninety-nine".