2121153731 has 4 divisors (see below), whose sum is σ = 2121909000. Its totient is φ = 2120398464.

The previous prime is 2121153707. The next prime is 2121153739. The reversal of 2121153731 is 1373511212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2121153731 is a prime.

It is a super-2 number, since 2×2121153731² = 8998586301070440722, which 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 2121153731.

It is not an unprimeable number, because it can be changed into a prime (2121153739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 373406 + ... + 379043.

It is an arithmetic number, because the mean of its divisors is an integer number (530477250).

Almost surely, 2^2121153731 is an apocalyptic number.

2121153731 is a deficient number, since it is larger than the sum of its proper divisors (755269).

2121153731 is an equidigital number, since it uses as much as digits as its factorization.

2121153731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 755268.

The product of its digits is 1260, while the sum is 26.

The square root of 2121153731 is about 46055.9847468274. The cubic root of 2121153731 is about 1284.8646530876.

Adding to 2121153731 its reverse (1373511212), we get a palindrome (3494664943).

The spelling of 2121153731 in words is "two billion, one hundred twenty-one million, one hundred fifty-three thousand, seven hundred thirty-one".