21076040 has 32 divisors (see below), whose sum is σ = 49059000. Its totient is φ = 8139264.

The previous prime is 21076037. The next prime is 21076043. The reversal of 21076040 is 4067012.

It is an interprime number because it is at equal distance from previous prime (21076037) and next prime (21076043).

It can be written as a sum of positive squares in 4 ways, for example, as 13380964 + 7695076 = 3658^2 + 2774^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (21076043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7925 + ... + 10244.

Almost surely, 2^21076040 is an apocalyptic number.

21076040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21076040 is an abundant number, since it is smaller than the sum of its proper divisors (27982960).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21076040 is a wasteful number, since it uses less digits than its factorization.

21076040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18209 (or 18205 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 21076040 is about 4590.8648422710. The cubic root of 21076040 is about 276.2250142905.

Subtracting from 21076040 its reverse (4067012), we obtain a triangular number (17009028 = T₅₈₃₂).

The spelling of 21076040 in words is "twenty-one million, seventy-six thousand, forty".