21461253207 has 8 divisors (see below), whose sum is σ = 28977219840. Its totient is φ = 14126394360.

The previous prime is 21461253199. The next prime is 21461253263. The reversal of 21461253207 is 70235216412.

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

It is not a de Polignac number, because 21461253207 - 2³ = 21461253199 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21461253707) 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, 45276669 + ... + 45277142.

It is an arithmetic number, because the mean of its divisors is an integer number (3622152480).

Almost surely, 2^21461253207 is an apocalyptic number.

21461253207 is a deficient number, since it is larger than the sum of its proper divisors (7515966633).

21461253207 is an equidigital number, since it uses as much as digits as its factorization.

21461253207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90553893.

The product of its (nonzero) digits is 20160, while the sum is 33.

Adding to 21461253207 its reverse (70235216412), we get a palindrome (91696469619).

The spelling of 21461253207 in words is "twenty-one billion, four hundred sixty-one million, two hundred fifty-three thousand, two hundred seven".