210821012 has 12 divisors (see below), whose sum is σ = 390639060. Its totient is φ = 99209856.

The previous prime is 210821003. The next prime is 210821021. The reversal of 210821012 is 210128012.

It is a happy number.

210821012 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (210821003) and next prime (210821021).

It can be written as a sum of positive squares in 2 ways, for example, as 135582736 + 75238276 = 11644^2 + 8674^2 .

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1550087 + ... + 1550222.

It is an arithmetic number, because the mean of its divisors is an integer number (32553255).

Almost surely, 2^210821012 is an apocalyptic number.

It is an amenable number.

210821012 is a deficient number, since it is larger than the sum of its proper divisors (179818048).

210821012 is a wasteful number, since it uses less digits than its factorization.

210821012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3100330 (or 3100328 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 210821012 is about 14519.6767181642. The cubic root of 210821012 is about 595.1657961337.

Adding to 210821012 its reverse (210128012), we get a palindrome (420949024).

The spelling of 210821012 in words is "two hundred ten million, eight hundred twenty-one thousand, twelve".