31552421 has 2 divisors, whose sum is σ = 31552422. Its totient is φ = 31552420.

The previous prime is 31552403. The next prime is 31552429. The reversal of 31552421 is 12425513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27984100 + 3568321 = 5290^2 + 1889^2 .

It is a cyclic number.

It is not a de Polignac number, because 31552421 - 2¹⁸ = 31290277 is a prime.

It is a super-2 number, since 2×31552421² = 1991110541922482, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31552429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15776210 + 15776211.

It is an arithmetic number, because the mean of its divisors is an integer number (15776211).

Almost surely, 2^31552421 is an apocalyptic number.

It is an amenable number.

31552421 is a deficient number, since it is larger than the sum of its proper divisors (1).

31552421 is an equidigital number, since it uses as much as digits as its factorization.

31552421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1200, while the sum is 23.

The square root of 31552421 is about 5617.1541727106. The cubic root of 31552421 is about 315.9930732071.

Adding to 31552421 its reverse (12425513), we get a palindrome (43977934).

The spelling of 31552421 in words is "thirty-one million, five hundred fifty-two thousand, four hundred twenty-one".