1021640190 has 64 divisors (see below), whose sum is σ = 2508475392. Its totient is φ = 266198400.

The previous prime is 1021640171. The next prime is 1021640209. The reversal of 1021640190 is 910461201.

It is an interprime number because it is at equal distance from previous prime (1021640171) and next prime (1021640209).

It is a super-2 number, since 2×1021640190² = 2087497355646472200, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1021640190.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 429705 + ... + 432075.

It is an arithmetic number, because the mean of its divisors is an integer number (39194928).

Almost surely, 2^1021640190 is an apocalyptic number.

1021640190 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1021640190, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1254237696).

1021640190 is an abundant number, since it is smaller than the sum of its proper divisors (1486835202).

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

1021640190 is a wasteful number, since it uses less digits than its factorization.

1021640190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2705.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 1021640190 is about 31963.1067013205. The cubic root of 1021640190 is about 1007.1619802501.

The spelling of 1021640190 in words is "one billion, twenty-one million, six hundred forty thousand, one hundred ninety".