21131037 has 12 divisors (see below), whose sum is σ = 31653440. Its totient is φ = 14087196.

The previous prime is 21131029. The next prime is 21131039. The reversal of 21131037 is 73013112.

It is not a de Polignac number, because 21131037 - 2³ = 21131029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131039) 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 11 ways as a sum of consecutive naturals, for example, 43237 + ... + 43722.

Almost surely, 2^21131037 is an apocalyptic number.

21131037 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21131037 is a deficient number, since it is larger than the sum of its proper divisors (10522403).

21131037 is an frugal number, since it uses more digits than its factorization.

21131037 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86974 (or 86962 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 18.

The square root of 21131037 is about 4596.8507698206. The cubic root of 21131037 is about 276.4650712832.

Adding to 21131037 its reverse (73013112), we get a palindrome (94144149).

The spelling of 21131037 in words is "twenty-one million, one hundred thirty-one thousand, thirty-seven".