2631690 has 84 divisors (see below), whose sum is σ = 7495794. Its totient is φ = 664848.

The previous prime is 2631689. The next prime is 2631691. The reversal of 2631690 is 961362.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2631689) and next prime (2631691).

It can be written as a sum of positive squares in only one way, i.e., 2368521 + 263169 = 1539^2 + 513^2 .

It is a super-2 number, since 2×2631690² = 13851584512200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a zygodrome in base 4.

It is not an unprimeable number, because it can be changed into a prime (2631691) by changing a digit.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 138501 + ... + 138519.

2^2631690 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2631690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3747897).

2631690 is an abundant number, since it is smaller than the sum of its proper divisors (4864104).

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

2631690 is an equidigital number, since it uses as much as digits as its factorization.

2631690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63 (or 29 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 2631690 is about 1622.2484396664. The cubic root of 2631690 is about 138.0632979941.

It can be divided in two parts, 2631 and 690, that added together give a triangular number (3321 = T₈₁).

The spelling of 2631690 in words is "two million, six hundred thirty-one thousand, six hundred ninety".