21457390071 has 16 divisors (see below), whose sum is σ = 31014663680. Its totient is φ = 13117096800.

The previous prime is 21457390037. The next prime is 21457390081. The reversal of 21457390071 is 17009375412.

It is not a de Polignac number, because 21457390071 - 2⁹ = 21457389559 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21457390081) 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, 1815931 + ... + 1827708.

It is an arithmetic number, because the mean of its divisors is an integer number (1938416480).

Almost surely, 2^21457390071 is an apocalyptic number.

21457390071 is a deficient number, since it is larger than the sum of its proper divisors (9557273609).

21457390071 is a wasteful number, since it uses less digits than its factorization.

21457390071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3643806.

The product of its (nonzero) digits is 52920, while the sum is 39.

The spelling of 21457390071 in words is "twenty-one billion, four hundred fifty-seven million, three hundred ninety thousand, seventy-one".