21011400831 has 16 divisors (see below), whose sum is σ = 28760030208. Its totient is φ = 13636651200.

The previous prime is 21011400811. The next prime is 21011400859. The reversal of 21011400831 is 13800411012.

It is a happy number.

It is not a de Polignac number, because 21011400831 - 2¹⁷ = 21011269759 is a prime.

It is a super-2 number, since 2×21011400831² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21011400798 and 21011400807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011400811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 125455 + ... + 240336.

It is an arithmetic number, because the mean of its divisors is an integer number (1797501888).

Almost surely, 2^21011400831 is an apocalyptic number.

21011400831 is a deficient number, since it is larger than the sum of its proper divisors (7748629377).

21011400831 is a wasteful number, since it uses less digits than its factorization.

21011400831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366302.

The product of its (nonzero) digits is 192, while the sum is 21.

Adding to 21011400831 its reverse (13800411012), we get a palindrome (34811811843).

The spelling of 21011400831 in words is "twenty-one billion, eleven million, four hundred thousand, eight hundred thirty-one".