31540072 has 8 divisors (see below), whose sum is σ = 59137650. Its totient is φ = 15770032.

The previous prime is 31540063. The next prime is 31540099. The reversal of 31540072 is 27004513.

It can be written as a sum of positive squares in only one way, i.e., 31069476 + 470596 = 5574^2 + 686^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×31540072² = 1989552283530368, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1971247 + ... + 1971262.

Almost surely, 2^31540072 is an apocalyptic number.

It is an amenable number.

31540072 is a deficient number, since it is larger than the sum of its proper divisors (27597578).

31540072 is a wasteful number, since it uses less digits than its factorization.

31540072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3942515 (or 3942511 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 31540072 is about 5616.0548430371. The cubic root of 31540072 is about 315.9518433265.

Adding to 31540072 its reverse (27004513), we get a palindrome (58544585).

The spelling of 31540072 in words is "thirty-one million, five hundred forty thousand, seventy-two".