21071492 has 12 divisors (see below), whose sum is σ = 39711756. Its totient is φ = 9725280.

The previous prime is 21071489. The next prime is 21071497. The reversal of 21071492 is 29417012.

It can be written as a sum of positive squares in 2 ways, for example, as 6677056 + 14394436 = 2584^2 + 3794^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is not an unprimeable number, because it can be changed into a prime (21071497) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 202559 + ... + 202662.

It is an arithmetic number, because the mean of its divisors is an integer number (3309313).

Almost surely, 2^21071492 is an apocalyptic number.

It is an amenable number.

21071492 is a deficient number, since it is larger than the sum of its proper divisors (18640264).

21071492 is a wasteful number, since it uses less digits than its factorization.

21071492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405238 (or 405236 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 21071492 is about 4590.3694840394. The cubic root of 21071492 is about 276.2051439901.

The spelling of 21071492 in words is "twenty-one million, seventy-one thousand, four hundred ninety-two".