21401011 has 16 divisors (see below), whose sum is σ = 24278400. Its totient is φ = 18741888.

The previous prime is 21400997. The next prime is 21401047. The reversal of 21401011 is 11010412.

It is not a de Polignac number, because 21401011 - 2⁵ = 21400979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21401071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18496 + ... + 19618.

It is an arithmetic number, because the mean of its divisors is an integer number (1517400).

Almost surely, 2^21401011 is an apocalyptic number.

21401011 is a deficient number, since it is larger than the sum of its proper divisors (2877389).

21401011 is a wasteful number, since it uses less digits than its factorization.

21401011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1218.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 21401011 is about 4626.1226745516. The cubic root of 21401011 is about 277.6374818585.

Adding to 21401011 its reverse (11010412), we get a palindrome (32411423).

The spelling of 21401011 in words is "twenty-one million, four hundred one thousand, eleven".