20621707 has 4 divisors (see below), whose sum is σ = 21707080. Its totient is φ = 19536336.

The previous prime is 20621693. The next prime is 20621759. The reversal of 20621707 is 70712602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 70712602 = 2 ⋅35356301.

It is a cyclic number.

It is not a de Polignac number, because 20621707 - 2¹⁹ = 20097419 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20621807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 542658 + ... + 542695.

It is an arithmetic number, because the mean of its divisors is an integer number (5426770).

Almost surely, 2^20621707 is an apocalyptic number.

20621707 is a deficient number, since it is larger than the sum of its proper divisors (1085373).

20621707 is a wasteful number, since it uses less digits than its factorization.

20621707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1085372.

The product of its (nonzero) digits is 1176, while the sum is 25.

The square root of 20621707 is about 4541.1129693061. The cubic root of 20621707 is about 274.2257317192.

The spelling of 20621707 in words is "twenty million, six hundred twenty-one thousand, seven hundred seven".