20513251311 has 32 divisors (see below), whose sum is σ = 31837378560. Its totient is φ = 11506420224.

The previous prime is 20513251309. The next prime is 20513251313. The reversal of 20513251311 is 11315231502.

It is an interprime number because it is at equal distance from previous prime (20513251309) and next prime (20513251313).

It is not a de Polignac number, because 20513251311 - 2¹ = 20513251309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20513251313) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 251271 + ... + 322743.

It is an arithmetic number, because the mean of its divisors is an integer number (994918080).

Almost surely, 2^20513251311 is an apocalyptic number.

20513251311 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20513251311 is a deficient number, since it is larger than the sum of its proper divisors (11324127249).

20513251311 is a wasteful number, since it uses less digits than its factorization.

20513251311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71735.

The product of its (nonzero) digits is 900, while the sum is 24.

Adding to 20513251311 its reverse (11315231502), we get a palindrome (31828482813).

The spelling of 20513251311 in words is "twenty billion, five hundred thirteen million, two hundred fifty-one thousand, three hundred eleven".