21000350501 has 24 divisors (see below), whose sum is σ = 23149516104. Its totient is φ = 19036892160.

The previous prime is 21000350479. The next prime is 21000350509. The reversal of 21000350501 is 10505300012.

It can be written as a sum of positive squares in 12 ways, for example, as 12522729025 + 8477621476 = 111905^2 + 92074^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21000350501 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21000350501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000350509) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8833625 + ... + 8836001.

It is an arithmetic number, because the mean of its divisors is an integer number (964563171).

Almost surely, 2^21000350501 is an apocalyptic number.

It is an amenable number.

21000350501 is a deficient number, since it is larger than the sum of its proper divisors (2149165603).

21000350501 is a wasteful number, since it uses less digits than its factorization.

21000350501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3321 (or 3308 counting only the distinct ones).

The product of its (nonzero) digits is 150, while the sum is 17.

Adding to 21000350501 its reverse (10505300012), we get a palindrome (31505650513).

The spelling of 21000350501 in words is "twenty-one billion, three hundred fifty thousand, five hundred one".