31221601 has 4 divisors (see below), whose sum is σ = 31322304. Its totient is φ = 31120900.

The previous prime is 31221587. The next prime is 31221607. The reversal of 31221601 is 10612213.

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 a cyclic number.

It is not a de Polignac number, because 31221601 - 2⁷ = 31221473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31221607) 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, 49885 + ... + 50506.

It is an arithmetic number, because the mean of its divisors is an integer number (7830576).

Almost surely, 2^31221601 is an apocalyptic number.

It is an amenable number.

31221601 is a deficient number, since it is larger than the sum of its proper divisors (100703).

31221601 is a wasteful number, since it uses less digits than its factorization.

31221601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100702.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 31221601 is about 5587.6292826207. The cubic root of 31221601 is about 314.8848188948.

Adding to 31221601 its reverse (10612213), we get a palindrome (41833814).

The spelling of 31221601 in words is "thirty-one million, two hundred twenty-one thousand, six hundred one".