21010131 has 8 divisors (see below), whose sum is σ = 31126160. Its totient is φ = 14006736.

The previous prime is 21010127. The next prime is 21010153. The reversal of 21010131 is 13101012.

It is not a de Polignac number, because 21010131 - 2² = 21010127 is a prime.

It is a super-2 number, since 2×21010131² = 882851209274322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21010111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 389050 + ... + 389103.

It is an arithmetic number, because the mean of its divisors is an integer number (3890770).

Almost surely, 2^21010131 is an apocalyptic number.

21010131 is a deficient number, since it is larger than the sum of its proper divisors (10116029).

21010131 is an equidigital number, since it uses as much as digits as its factorization.

21010131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 778162 (or 778156 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 9.

The square root of 21010131 is about 4583.6809443939. The cubic root of 21010131 is about 275.9367766338.

Adding to 21010131 its reverse (13101012), we get a palindrome (34111143).

The spelling of 21010131 in words is "twenty-one million, ten thousand, one hundred thirty-one".