21739253707 has 2 divisors, whose sum is σ = 21739253708. Its totient is φ = 21739253706.

The previous prime is 21739253699. The next prime is 21739253771. The reversal of 21739253707 is 70735293712.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21739253707 - 2³ = 21739253699 is a prime.

It is not a weakly prime, because it can be changed into another prime (21739253507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10869626853 + 10869626854.

It is an arithmetic number, because the mean of its divisors is an integer number (10869626854).

Almost surely, 2^21739253707 is an apocalyptic number.

21739253707 is a deficient number, since it is larger than the sum of its proper divisors (1).

21739253707 is an equidigital number, since it uses as much as digits as its factorization.

21739253707 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 555660, while the sum is 46.

The spelling of 21739253707 in words is "twenty-one billion, seven hundred thirty-nine million, two hundred fifty-three thousand, seven hundred seven".