21151011 has 16 divisors (see below), whose sum is σ = 32534784. Its totient is φ = 11972064.

The previous prime is 21150991. The next prime is 21151027. The reversal of 21151011 is 11015112.

It is not a de Polignac number, because 21151011 - 2⁵ = 21150979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21151061) 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, 2460 + ... + 6953.

It is an arithmetic number, because the mean of its divisors is an integer number (2033424).

Almost surely, 2^21151011 is an apocalyptic number.

21151011 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21151011 is a deficient number, since it is larger than the sum of its proper divisors (11383773).

21151011 is a wasteful number, since it uses less digits than its factorization.

21151011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9530.

The product of its (nonzero) digits is 10, while the sum is 12.

The square root of 21151011 is about 4599.0228309936. The cubic root of 21151011 is about 276.5521528958.

Adding to 21151011 its reverse (11015112), we get a palindrome (32166123).

The spelling of 21151011 in words is "twenty-one million, one hundred fifty-one thousand, eleven".