21372007 has 2 divisors, whose sum is σ = 21372008. Its totient is φ = 21372006.

The previous prime is 21371993. The next prime is 21372011. The reversal of 21372007 is 70027312.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21372007 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21372047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10686003 + 10686004.

It is an arithmetic number, because the mean of its divisors is an integer number (10686004).

Almost surely, 2^21372007 is an apocalyptic number.

21372007 is a deficient number, since it is larger than the sum of its proper divisors (1).

21372007 is an equidigital number, since it uses as much as digits as its factorization.

21372007 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 588, while the sum is 22.

The square root of 21372007 is about 4622.9868050861. The cubic root of 21372007 is about 277.5120012124.

Adding to 21372007 its reverse (70027312), we get a palindrome (91399319).

It can be divided in two parts, 213 and 72007, that multiplied together give a triangular number (15337491 = T₅₅₃₈).

The spelling of 21372007 in words is "twenty-one million, three hundred seventy-two thousand, seven".