31400661 has 4 divisors (see below), whose sum is σ = 41867552. Its totient is φ = 20933772.

The previous prime is 31400659. The next prime is 31400669. The reversal of 31400661 is 16600413.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16600413 = 3 ⋅5533471.

It is not a de Polignac number, because 31400661 - 2¹ = 31400659 is a prime.

It is a super-2 number, since 2×31400661² = 1972003022473842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31400669) 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, 5233441 + ... + 5233446.

It is an arithmetic number, because the mean of its divisors is an integer number (10466888).

Almost surely, 2^31400661 is an apocalyptic number.

It is an amenable number.

31400661 is a deficient number, since it is larger than the sum of its proper divisors (10466891).

31400661 is a wasteful number, since it uses less digits than its factorization.

31400661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10466890.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 31400661 is about 5603.6292703925. The cubic root of 31400661 is about 315.4856404146.

The spelling of 31400661 in words is "thirty-one million, four hundred thousand, six hundred sixty-one".