21162739 has 16 divisors (see below), whose sum is σ = 24917760. Its totient is φ = 17786880.

The previous prime is 21162727. The next prime is 21162749. The reversal of 21162739 is 93726112.

It is a cyclic number.

It is not a de Polignac number, because 21162739 - 2¹³ = 21154547 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

21162739 is a Rhonda number in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 21162739.

It is not an unprimeable number, because it can be changed into a prime (21162709) 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, 5307 + ... + 8395.

It is an arithmetic number, because the mean of its divisors is an integer number (1557360).

Almost surely, 2^21162739 is an apocalyptic number.

21162739 is a deficient number, since it is larger than the sum of its proper divisors (3755021).

21162739 is a wasteful number, since it uses less digits than its factorization.

21162739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3150.

The product of its digits is 4536, while the sum is 31.

The square root of 21162739 is about 4600.2977077576. The cubic root of 21162739 is about 276.6032584806.

The spelling of 21162739 in words is "twenty-one million, one hundred sixty-two thousand, seven hundred thirty-nine".