40313981 has 4 divisors (see below), whose sum is σ = 41614464. Its totient is φ = 39013500.

The previous prime is 40313929. The next prime is 40313983. The reversal of 40313981 is 18931304.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 40313981 - 2¹⁴ = 40297597 is a prime.

It is a super-2 number, since 2×40313981² = 3250434128136722, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 7.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40313983) 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, 650195 + ... + 650256.

It is an arithmetic number, because the mean of its divisors is an integer number (10403616).

Almost surely, 2^40313981 is an apocalyptic number.

It is an amenable number.

40313981 is a deficient number, since it is larger than the sum of its proper divisors (1300483).

40313981 is a wasteful number, since it uses less digits than its factorization.

40313981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1300482.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 40313981 is about 6349.3291771651. The cubic root of 40313981 is about 342.8876914166.

The spelling of 40313981 in words is "forty million, three hundred thirteen thousand, nine hundred eighty-one".