21425037646 has 16 divisors (see below), whose sum is σ = 32293183104. Its totient is φ = 10660677984.

The previous prime is 21425037643. The next prime is 21425037649. The reversal of 21425037646 is 64673052412.

It is an interprime number because it is at equal distance from previous prime (21425037643) and next prime (21425037649).

It is a junction number, because it is equal to n+sod(n) for n = 21425037599 and 21425037608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21425037643) 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, 1568920 + ... + 1582516.

It is an arithmetic number, because the mean of its divisors is an integer number (2018323944).

Almost surely, 2^21425037646 is an apocalyptic number.

21425037646 is a deficient number, since it is larger than the sum of its proper divisors (10868145458).

21425037646 is a wasteful number, since it uses less digits than its factorization.

21425037646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17355.

The product of its (nonzero) digits is 241920, while the sum is 40.

The spelling of 21425037646 in words is "twenty-one billion, four hundred twenty-five million, thirty-seven thousand, six hundred forty-six".