40021396 has 6 divisors (see below), whose sum is σ = 70037450. Its totient is φ = 20010696.

The previous prime is 40021381. The next prime is 40021409. The reversal of 40021396 is 69312004.

It can be written as a sum of positive squares in only one way, i.e., 35569296 + 4452100 = 5964^2 + 2110^2 .

It is a super-3 number, since 3×40021396³ (a number of 24 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 40021396.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5002671 + ... + 5002678.

Almost surely, 2^40021396 is an apocalyptic number.

It is an amenable number.

40021396 is a deficient number, since it is larger than the sum of its proper divisors (30016054).

40021396 is a wasteful number, since it uses less digits than its factorization.

40021396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10005353 (or 10005351 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 40021396 is about 6326.2465965215. The cubic root of 40021396 is about 342.0561562085.

The spelling of 40021396 in words is "forty million, twenty-one thousand, three hundred ninety-six".