31553343021 has 8 divisors (see below), whose sum is σ = 42077757184. Its totient is φ = 21032245440.

The previous prime is 31553343011. The next prime is 31553343023. The reversal of 31553343021 is 12034335513.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31553343021 - 2¹⁹ = 31552818733 is a prime.

It is a super-2 number, since 2×31553343021² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31553343021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31553343023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 806860 + ... + 845061.

It is an arithmetic number, because the mean of its divisors is an integer number (5259719648).

Almost surely, 2^31553343021 is an apocalyptic number.

It is an amenable number.

31553343021 is a deficient number, since it is larger than the sum of its proper divisors (10524414163).

31553343021 is a wasteful number, since it uses less digits than its factorization.

31553343021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1658291.

The product of its (nonzero) digits is 16200, while the sum is 30.

Adding to 31553343021 its reverse (12034335513), we get a palindrome (43587678534).

The spelling of 31553343021 in words is "thirty-one billion, five hundred fifty-three million, three hundred forty-three thousand, twenty-one".