21151017 has 16 divisors (see below), whose sum is σ = 31469760. Its totient is φ = 14040000.

The previous prime is 21150991. The next prime is 21151027. The reversal of 21151017 is 71015112.

It is a happy number.

It is not a de Polignac number, because 21151017 - 2¹⁰ = 21149993 is a prime.

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21151027) 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, 5217 + ... + 8337.

It is an arithmetic number, because the mean of its divisors is an integer number (1966860).

Almost surely, 2^21151017 is an apocalyptic number.

21151017 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21151017 is a deficient number, since it is larger than the sum of its proper divisors (10318743).

21151017 is a wasteful number, since it uses less digits than its factorization.

21151017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3381 (or 3375 counting only the distinct ones).

The product of its (nonzero) digits is 70, while the sum is 18.

The square root of 21151017 is about 4599.0234833060. The cubic root of 21151017 is about 276.5521790460.

Adding to 21151017 its reverse (71015112), we get a palindrome (92166129).

The spelling of 21151017 in words is "twenty-one million, one hundred fifty-one thousand, seventeen".