21030690 has 16 divisors (see below), whose sum is σ = 50473728. Its totient is φ = 5608176.

The previous prime is 21030677. The next prime is 21030703. The reversal of 21030690 is 9603012.

It is an interprime number because it is at equal distance from previous prime (21030677) and next prime (21030703).

It is a super-2 number, since 2×21030690² = 884579843752200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 350482 + ... + 350541.

It is an arithmetic number, because the mean of its divisors is an integer number (3154608).

Almost surely, 2^21030690 is an apocalyptic number.

21030690 is an abundant number, since it is smaller than the sum of its proper divisors (29443038).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21030690 is a wasteful number, since it uses less digits than its factorization.

21030690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 701033.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 21030690 is about 4585.9230259567. The cubic root of 21030690 is about 276.0267512403.

The spelling of 21030690 in words is "twenty-one million, thirty thousand, six hundred ninety".